This will potentially fix a number of Alacritty related panics, however
it is tricky to figure out which ones in particular will be impacted for
sure. We've said we were going to do this for a while but with the
constant trickle of panics it seemed reasonable to just go and do it

Release Notes:

- Fixed a few potential terminal related crashes.

Our dependency on `tree-sitter-cpp` got upgraded to an incompatible
version despite semver 'guarantees'. This pins the dependency onto the
commit of version 0.20.0

Release Notes:

- Restored language detection for C++ (preview-only)

Release Notes:

- Added documentation about theme types generation

This should be a purely internal change. Let me know if any visual
changes are observed from this!

### Syntax theme
- Update the theme to allow any syntax highlighting property used in any
`highlight.scm` to be styled
- Only define syntax styles that are baked into the default theme &
don't use the default text style
- Adds the `generate-syntax` command
- Removes a few unused properties that we were styling for some reason,
like `enum` and `variant`, neither of which exist in any `highlight.scm`
- Moves `@constructor` symbols to `@method.constructor` to prevent
issues with `constructor` being a reserved property in ts/js.

Syntax is now build as the theme is created rather than as part of the
styleTree. This means it no longer requires a compiled `Theme`, which
makes things a bit more straightforward if we need to access it in other
components that should be built before the styleTrees.

### Scheme

Also updates all uses of `#match` in our `highlights.scm` files, as
these break the scheme tree-sitter query. This fixes _most_ instances of
our scheme highlighting breaking.

For some reason something in here breaks the `highlights.scm` for PHP:

```scheme
((name) @constant.builtin
 (.match? @constant.builtin "^__[A-Z][A-Z\d_]+__$"))

((name) @method.constructor
(.match? @method.constructor "^[A-Z]"))

((name) @variable.builtin
 (.eq? @variable.builtin "this"))
```

Release Notes:

- No public facing changes

uses of `#` cause ERRORs in our scheme highlighting

The status bar diagnostic message font size was updated in
https://github.com/zed-industries/zed/commit/1f65effe57b85d126fcb5689d6d37ec3f768502e
but the LSP status message font size remained the same causing a font
size change when swapping between the two

![CleanShot 2023-07-26 at 18 32
13](https://github.com/zed-industries/zed/assets/30666851/8d357f46-3a48-4ed1-9832-d24b4b2be4a8)
![CleanShot 2023-07-26 at 18 30
56](https://github.com/zed-industries/zed/assets/30666851/e4ce9911-f66d-4bc3-b951-78196da44176)

Release Notes:

- Fixed an inconsistency in status bar font size.

Move result count to the left hand side.

This fixes a bug that could cause the cursor to incorrectly report its
start when using `slice` or `seek_forward`, and then calling `prev`. We
didn't notice this because we were not testing those three methods
together.

I suppose this could explain some of the panics we've observed because
we do use `slice`/`seek_forward` followed by `prev` calls in production.

Move semantic & regex buttons to the right hand side.
Add default tab name for the new project search.

This fixes a bug that could cause the cursor to incorrectly report its
start when using `slice` or `seek_forward`, and then calling `prev`. We
didn't notice this because we were not testing those three methods
together.

I suppose this could explain some of the panics we've observed because
we do use `slice`/`seek_forward` followed by `prev` calls in production.

The tree sitter elm parser contains a c symbol which collides with other
linked symbols. This PR downgrades the tree sitter elm parser to a
version which doesn't have this problem.

Release Notes:
- Fixed crash when parsing elm files

In https://github.com/zed-industries/zed/pull/2790 I added an extra drag
event on mouse_up which signaled the end of a drag event, as mouse_up
event themselves wouldn't reliably fire if users moved their mouse too
quickly. This broke the assumptions of the terminal element. This PR
adds filters to all current on_drag handlers which removes this new
event.

Release Notes:

- Fixed a bug causing terminal links to never open (preview only)
- Fixed a bug in terminal link detection causing it to miss files with a
`-` in it

Parallelize Vector Database calls for project semantic search.

Release Notes: (Preview-only)

- Parallelize Vector database calls for project semantic search. Cuts
query time by 2/3rds.
- Removed default keymap for old semantic search modal.

Updated app icon and icon system updates

This PR cascades the split resizing to adjacent splits, if the current
split has already hit the minimum size. This PR also adds support for
detecting the end of a drag event to GPUI, via a bool on the dispatched
drag.

Release Notes:

- Made split resizing more flexible

Move semantic search from navigation modal, to project search option.
This PR is intended to be released in Preview only, and requires an
opt-in semantic_index option to enable. Without this opt-in setting
enable, the user should perceive no differences between previous project
search.

Release Notes: (Preview-only)

- Added Semantic Search as a opt-in feature within Project Search
- Show indexing feedback on indexing process within project search view