The formatting of the empty pane text regressed in #3665, in which I
also made it possible to drag items onto an empty pane.

Reimplement the pane drag targets using on_drag_move

Reimplement the pane drag targets using on_drag_move

This fixes some bugs in the display and tracking of dock resizes

Release Notes:

-

co-authored-by: conrad <conrad@zed.dev>

This PR fixes a warning that was present in release mode, which was
preventing the nightly builds from running:

```
error: variable does not need to be mutable
   --> crates/gpui2/src/elements/div.rs:547:9
    |
547 |     let mut div = Div {
    |         ----^^^
    |         |
    |         help: remove this `mut`
    |
    = note: `-D unused-mut` implied by `-D warnings`
```

Release Notes:

- N/A

co-authored-by: conrad <conrad@zed.dev>

This PR populates the `editor_foreground` color in the various themes
and updates the editor to use this as the color for text.

The `text` field in the theme should now be used for UI elements, while
`editor_foreground` should be used for buffers.

This improves the contrast in some themes, notably Ayu Dark.

Release Notes:

- N/A

Co-authored-by: Conrad <conrad@zed.dev>

Bring back some workspace tests

Co-authored-by: Conrad <conrad@zed.dev>

Rework gpui2 drag API so that receivers need not specify the dragged
view type.

co-authored-by: Conrad <conrad@zed.dev>

Rework gpui2 drag API so that receivers need not specify the dragged view type.

co-authored-by: Max <max@zed.dev>
co-authored-by: Conrad <conrad@zed.dev>

This PR styles the "Replace in project" input in the project search.

Release Notes:

- N/A

Co-Authored-By: Marshall Bowers <1486634+maxdeviant@users.noreply.github.com>

Fixes clicking in the top/bottom 100px of the editor


Release Notes:

- N/A

This PR styles the inputs in the project search.

<img width="772" alt="Screenshot 2023-12-14 at 1 53 28 PM"
src="https://github.com/zed-industries/zed/assets/1486634/fe2362be-79db-4551-a473-2acf7a8a1bcb">

Release Notes:

- N/A

This PR makes the toolbar hide itself if it has no visible items.

This removes the double border beneath the tab bar when there are no
visible tools in the toolbar.

Release Notes:

- N/A

* Ensure that scroll events from blocks scroll the editor
* Ensure that scroll bars show behind hover things

This PR builds on top of #3652 by adding a selection prompt to the
storybook to allow you to choose from the available list of stories if
you don't provide one explicitly:

<img width="1387" alt="Screenshot 2023-12-14 at 12 00 26 PM"
src="https://github.com/zed-industries/zed/assets/1486634/640d62a3-1340-45f1-9746-69b513faff62">

This way we don't have to keep generating the `script/storybook` script
whenever stories are added/removed.

#### Usage (through `cargo`):

```sh
# Select from the available stories
cargo run -p storybook2

# Run a specific story
cargo run -p storybook2 -- components/list_item
```

#### Usage (through `script/storybook`):

```sh
# Select from the available stories
./script/storybook

# Run a specific story
./script/storybook list_item
```

Release Notes:

- N/A

[[PR Description]]

This PR adds the ability to run stories with `script/storybook`.

Running it directly will give you a selector like this:

```zsh
➜  zed git:(add-storybook-script) script/storybook
1) auto_height_editor	 9) icon		17) scroll
2) avatar		10) icon_button		18) tab
3) button		11) keybinding		19) tab_bar
4) checkbox		12) label		20) text
5) context_menu		13) list		21) viewport_units
6) cursor		14) list_header		22) z_index
7) disclosure		15) list_item		23) picker
8) focus		16) overflow_scroll
```

You can also provide a value like:

`script/storybook {STORY_NAME}` - Example: `script/storybook text`

OR 

`script/storybook components/{STORY_NAME}` - Example: `script/storybook
components/text`

I just wanted an easier way to interface with stories quickly to make
using them a bit easier, and enable discovery of what exists easier with
the selector.

This was a really quick hack, in the future we can extend this to a
proper CLI.

Release Notes:

- N/A