Deals with https://github.com/zed-industries/community/issues/1317
Deals with https://github.com/zed-industries/community/issues/486

Reworks pane drag and drop code to support 
* dropping external files into main pane (supports splits same as tabs
and project entries drop) — this will open the file dropped
* dropping external files, tabs and project entries drop into the
terminal — this will add file abs path into the terminal

Release Notes:

- Added a way to drag and drop external files into Zed main & terminal
panes; support tabs and project entries drop into terminal pane

# TODO

- [x] Fix busted tests
- [x] Check all events from actions on welcome screen
    - [x] change theme
    - [x] change keymap
    - [x] install cli
    - [x] enable vim
    - [x] send metric data
    - [x] send diagnostics
    - [x] close welcome screen
- [X] Check all settings events
    - [x] record theme change (in main and in selector)
    - [x] record base keymap change (in main and in selector)
    - [x] record metric data value
    - [x] record diagnostics value
- [X] Triple check that telemetry settings still block events from being
sent, since we updated how we check for settings changes
- [X] Remove immediate flush mode and allow the flush method to be
called publicly
- [x] Remove references to clickhouse in the code (should be generic at
the client level)

Release Notes:

- N/A

The client sends events to our end point, and the endpoint is what determines what analytics database is used to store the data. The client should be generic and not mention the name of the service being proxied to through our server.

Allow flush method to be called publicly. This is a better, simpler solution, that allows for better control over flushing.

I essentially went through the publicly exported items and marked these
that are e.g. leaky reexports as pub(crate). I expect that'd be done on
Tuesday anyways.

Release Notes:
- N/A

Deals with https://github.com/zed-industries/community/issues/2367

Release Notes:

- Fixed file finder crashing on certain paths with multi-codepoint
characters
([#2367](https://github.com/zed-industries/community/issues/2367))

Release Notes:

- Fixed a bug that was causing Zed to use a lot of energy when moving
the mouse.

Release Notes:

- N/A

Release Notes:

- Fixed base keymap selector keyboard shortcuts

![CleanShot 2024-01-05 at 17 30
11@2x](https://github.com/zed-industries/zed/assets/1789/b70226d0-bc07-4ce3-b45d-c25aace998c2)

Release Notes:

- Fixed the alignment of the assistant headers and text
- Increased the left padding on the assistant.

Since the message headers are buttons, we need to shift them relatively to
compensate for the fact that the background is only visible when hovered.
I'm ok with the background not being aligned so long as the unhovered text is.

Release Notes:

- Restored collab button tooltips, made screenshare item background of
editor background's color

Starting work on the following tests.

* The first failure was caused by not properly dropping the references,
which is now fixed.
* The next failure is caused by a `cx.after_window_update` being changed
to `cx.on_next_frame`. This doesn't seem to work (at least in tests),
but might also explain the flaky following behavior Max and I observed
if there's a timing bug in production too.
* * When you are following someone and they move their cursor you should
receive two proto messages: UpdateBuffer to move the cursor, and
UpdateFollowers to update where you're following. It seems like this
could be made a bit less chatty/fragile, but probably out of scope for
this.
* With that worked around, there's one more failure, but I haven't
looked into it yet. (possibly caused by an incorrect fix for the cx
one).

Co-Authored-By: Max <max@zed.dev>

Co-Authored-By: Max <max@zed.dev>

Co-Authored-By: Max <max@zed.dev>

Co-Authored-By: Max <max@zed.dev>

* Fix an incorrect use of `Any::type_id` that prevented the disabling of
key bindings
* Restructured the representation of disabled key bindings so that they
handle context predicates correctly. Previously, to disable key binding,
you needed to supply the exact same context predicate (e.g. `Editor &&
mode == "full"`) as the binding that you are trying to disable. Now, the
context predicates of disabled key bindings are evaluated just like any
other context predicate (with the current context) to see if they apply.

Release Notes:

- Fixed an issue where disabling key bindings didn't work. To disable a
key binding, set it to `null` in your keymap.

This PR refines the design of the channel management modal:

#### Before

<img width="585" alt="Screenshot 2024-01-05 at 4 17 32 PM"
src="https://github.com/zed-industries/zed/assets/1486634/a6d96674-b688-4549-8fb8-0a7b2c7c88be">

#### After

<img width="589" alt="Screenshot 2024-01-05 at 4 15 20 PM"
src="https://github.com/zed-industries/zed/assets/1486634/31ae8dc1-a129-4a15-963e-9779b9b79bd9">

Release Notes:

- Improved the look of the channel management modal.

This PR tidies up the styling of the connection status indicators in the
title bar.

Removed some debug styles and tweaked the styling to match the rest of
the title bar overall.

Release Notes:

- Improved the connection status indicators in the title bar.

Bugs from the 0.34.0 collab nightly deploy