### Summary

This PR introduces channels: a new way of starting collaboration
sessions. You can create channels and invite others to join them. You
can then hold a call in a channel, where any member of the channel is
free to join the call without needing to be invited.

Channels are displayed in a new panel called the collaboration panel,
which now also contains the contacts list, and the current call. The
collaboration popover has been removed from the titlebar.

![Screen Shot 2023-08-15 at 9 25 37
AM](https://github.com/zed-industries/zed/assets/326587/0f989dea-7fb7-4d50-9acd-25c8f1c30cd1)


For now, the channels functionality will only be revealed to staff, so
the public-facing change is just the move from the popover to the panel.

### To-do

* User-facing UI
  * [x] signed-out state for collab panel
  * [x] new icon for collab panel
  * [x] for now, channels section only appears for zed staff
* [x] current call section styling
(https://zed-industries.slack.com/archives/C05CJUNF2BU/p1691189389988239?thread_ts=1691189120.403009&cid=C05CJUNF2BU)
* [x] Channel members
* Channels
  * [x] style channel name editor
* [x] decide on a special "empty state" for the panel, when user has no
contacts
* [x] ensure channels are sorted in a consistent way (expose channel id
paths to client)
  * [x] Figure out layered panels UX
  * [x] Change add contacts to be the same kind of tabbed modal
* [x] race condition between channel updates and user fetches
(`ChannelStore::handle_update_contacts`)
* [x] race condition between joining channels and channel update
messages `collab::rpc::channel_updated`)
* [x] don't display mic as muted when microphone share is pending upon
first joining call

Release Notes:

- Moved the collaboration dropdown into its own panel.
- Added settings for disabling the AI assistant panel button.
- Switch to lazily initializing audio output sources
(https://github.com/zed-industries/community/issues/1840,
https://github.com/zed-industries/community/issues/1919)

Co-Authored-By: Max Brunsfeld <maxbrunsfeld@gmail.com>

Co-Authored-By: Max Brunsfeld <maxbrunsfeld@gmail.com>

Before, terminal view focused the parent (pane) instead and, if
terminal's search bar was open and focused, pane transferred the focus
back

Release Notes:

- Fixed terminal search focus not switching to terminal on mouse click
inside

Before, terminal view focused the parent (pane) instead and, if
terminal's search bar was open and focused, pane transferred the focus
back

`cargo run` on Zed project leads to rust-analyzer evantually emitting

`[ERROR project_model::workspace] cyclic deps:
gpui_macros(Idx::<CrateData>(269)) -> gpui(Idx::<CrateData>(264)),
alternative path: gpui(Idx::<CrateData>(264)) ->
gpui_macros(Idx::<CrateData>(269))`

error after loading the project.

The PR fixes this by moving away the test to the "root" project.

Release Notes:

- N/A

`cargo run` on Zed project leads to rust-analyzer evantually emitting

`[ERROR project_model::workspace] cyclic deps:
gpui_macros(Idx::<CrateData>(269)) -> gpui(Idx::<CrateData>(264)),
alternative path: gpui(Idx::<CrateData>(264)) ->
gpui_macros(Idx::<CrateData>(269))`

error after loading the project.

The PR fixes this by moving away the test to the "root" project.

Release Notes:

- N/A

Co-authored-by: Mikayla <mikayla@zed.dev>

Co-authored-by: Mikayla <mikayla@zed.dev>

![image](https://github.com/zed-industries/zed/assets/2690773/3aae1e6a-9993-4e65-8ed1-20f2f4b452df)

Allows to use `editor::SelectAll`(`cmd-a` by default) in Terminal to
select all text in it, for future copying.
Currently, does not try to be smart and trim the selected whitespaces
after the last prompt, and copies them too.

Release Notes:

- Support `editor::SelectAll` in Terminal

Going to do these in batches.  Here is the first one.

Release Notes:

- Associated additional file extensions with known languages
(([#633](https://github.com/zed-industries/community/issues/633)),
([#1822](https://github.com/zed-industries/community/issues/1822))).
    - C++: `cxx`, `hxx`, `inl`
    - JavaScript: `cjs`
    - Python: `mpy`
    - TypeScript: `cts`, `d.cts`, `d.mts`, `mts`

Co-authored-by: Mikayla <mikayla@zed.dev>

co-authored-by: Nate <nate@zed.dev>

Update vim mode to have vim selection and editor selections match.
Before this we had to adjust between vim selections and real selections
when making changes; now we have to adjust when making selections.

Release Notes:

- vim: Ensure editor selection matches the vim selection
([#1796](https://github.com/zed-industries/community/issues/1796)).
- vim: Fix `s` in visual line mode
- vim: Add `o` and `shift-o` to toggle direction of visual selection
- vim: Fix `v` and `shift-v` to toggle back to normal mode
- vim: Fix block selections like `vi}` to contain correct whitespace

Fixes: zed-industries/community#1857

- vim: Fix escape in normal mode
([#1857](https://github.com/zed-industries/community/issues/1857)).

This PR is a continuation of the components UI exploration I've been
doing. It adds an example to the GPUI examples page and totally
restructures the generics on our MouseEventHandler.

Release Note:
- N/A

Re-arrange generics on mouse event handler
Add TypeTag struct for dynamically tagged components

Co-authored-by: Mikayla <mikayla@zed.dev>

Co-authored-by: Mikayla <mikayla@zed.dev>

Co-authored-by: Mikayla <mikayla@zed.dev>

Co-authored-by: Mikayla <mikayla@zed.dev>

Co-authored-by: Mikayla <mikayla@zed.dev>

Fixes: zed-industries/community#1857

Part of
https://linear.app/zed-industries/issue/Z-2750/investigate-performance-of-collaborating-on-large-files-with-inlay

Instead of querying the entire file for hints, query visible editor(s)
range + the areas above and below, of the same height.
Non-invalidating future queries (e.g. scrolling) query only missing
parts of the ranges.

Release Notes:

- Improved LSP resource usage by querying less hints for big files

Part of
https://linear.app/zed-industries/issue/Z-2750/investigate-performance-of-collaborating-on-large-files-with-inlay

* Declares client capabilities for hint resolution, marking both fields
available for resolution (`textEdits` and `tooltop`) as resolvable.
We do not use these fields anymore, hence can omit resolving them for
now, but LSP servers can omit them during general hint requests.

* Removes `tooltip` and replaces complex `label` with its simple string
counterpart for clients' hint responses from host: both should be
resolved through host later

Release Notes:

- Reduces collab mode clients' inlay hint footprint by enabling hint
data resolution