* Ensure channel list is in a consistent state with no flicker while the
  channel creation / rename request is outstanding.
* Maintain selection properly when renaming and creating channels.
* Style the channel name editor more consistently with the non-editable
  channel names.

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

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

Deals with https://github.com/zed-industries/community/issues/1898

Restores original close behavior from
https://github.com/zed-industries/zed/pull/2832/files#diff-89af0b4072205c53b518aa977d6be48997e1a51fa4dbf06c7ddd1fec99fc510eL444
(load diff for the last file, zed.rs)

and adds a better name for the variable.

Release Notes:

- Fixes `cmd-q` not working

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

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

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

This PR fixes two bugs we discovered in Zed's mouse event handling while
investigating an interesting and mysterious bug we we were seeing, where
spurious `MouseMoved` events would continuously be dispatched after
control-clicking.

Release Notes:

- Fixed a rendering glitch that could occur after control-clicking
certain elements.

This adds IBM Plex as a font option available to use as `ui_sans`

Note: This PR adds a static list of accepted font types in `/font`, as
LICENSE files were causing the app to crash when Zed was trying to load
them as fonts.

Release Notes:

- N/A (No user facing changes)

Thanks @ForLoveOfCats for getting me unstuck ❤️

Co-Authored-By: Julia <30666851+ForLoveOfCats@users.noreply.github.com>

Co-Authored-By: Julia <30666851+ForLoveOfCats@users.noreply.github.com>

(base) natebutler@Nate16 zed % cargo run
   Compiling zed v0.99.0 (/Users/natebutler/Code/zed/zed/crates/zed)
    Finished dev [unoptimized + debuginfo] target(s) in 9.15s
     Running `target/debug/Zed`
Thread "main" panicked with "called `Result::unwrap()` on an `Err` value: parse error" at crates/zed/src/main.rs:667:10
   0: backtrace::backtrace::libunwind::trace
             at /Users/natebutler/.cargo/registry/src/index.crates.io-6f17d22bba15001f/backtrace-0.3.68/src/backtrace/libunwind.rs:93:5
      backtrace::backtrace::trace_unsynchronized
             at /Users/natebutler/.cargo/registry/src/index.crates.io-6f17d22bba15001f/backtrace-0.3.68/src/backtrace/mod.rs:66:5
   1: backtrace::backtrace::trace
             at /Users/natebutler/.cargo/registry/src/index.crates.io-6f17d22bba15001f/backtrace-0.3.68/src/backtrace/mod.rs:53:14
   2: backtrace::capture::Backtrace::create
             at /Users/natebutler/.cargo/registry/src/index.crates.io-6f17d22bba15001f/backtrace-0.3.68/src/capture.rs:176:9
   3: backtrace::capture::Backtrace::new
             at /Users/natebutler/.cargo/registry/src/index.crates.io-6f17d22bba15001f/backtrace-0.3.68/src/capture.rs:140:22
   4: Zed::init_panic_hook::{{closure}}
             at crates/zed/src/main.rs:436:29
   5: std::panicking::rust_panic_with_hook
   6: std::panicking::begin_panic_handler::{{closure}}
   7: std::sys_common::backtrace::__rust_end_short_backtrace
   8: _rust_begin_unwind
   9: core::panicking::panic_fmt
  10: core::result::unwrap_failed
  11: core::result::Result<T,E>::unwrap
             at /private/tmp/rust-20230613-7622-103lepv/rustc-1.70.0-src/library/core/src/result.rs:1089:23
  12: Zed::load_embedded_fonts
             at crates/zed/src/main.rs:664:5
  13: Zed::main
             at crates/zed/src/main.rs:80:5
  14: core::ops::function::FnOnce::call_once
             at /private/tmp/rust-20230613-7622-103lepv/rustc-1.70.0-src/library/core/src/ops/function.rs:250:5
  15: std::sys_common::backtrace::__rust_begin_short_backtrace
             at /private/tmp/rust-20230613-7622-103lepv/rustc-1.70.0-src/library/std/src/sys_common/backtrace.rs:134:18
  16: std::rt::lang_start::{{closure}}
             at /private/tmp/rust-20230613-7622-103lepv/rustc-1.70.0-src/library/std/src/rt.rs:166:18
  17: std::panicking::try
  18: std::rt::lang_start_internal
  19: std::rt::lang_start
             at /private/tmp/rust-20230613-7622-103lepv/rustc-1.70.0-src/library/std/src/rt.rs:165:17
  20: _mai

I want to use this on another branch, but it's a sweeping change, so
this prepares the ground for it. This can always be reverted if it
doesn't work out.

I went to add in `zprofile` to the bash language config to get syntax
highlighting for it. After adding it in, Zed was still not highlighting
the file. I checked and saw that we are using `Path::extension()` in
`language_for_file()`, which [returns `None` when a file's name begins
with a
`.`](https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.extension),
such as in the case of `.zprofile`. This PR adds a custom method, with
some tests, that just tries to grab the last component in the file name
if `Path::extension` returns `None`. Not sure if `ext` is the best name,
but I can't use `extension`.

Maybe this method should be called `extension_or_hidden_file_name()`?

Release Notes:

- Fixed a bug where language detection would fail for files starting
with `.` in their names.
- Added syntax highlighting for `.zprofile` files

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

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

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

With this PR, I've eliminated almost all references to window ids
outside of the internals of GPUI. All public methods taking these ids
are now defined on `AnyWindowHandle`, which provides a more coherent
narrative around windows as a concept.