[[PR Description]]

A few mix organizational things in UI, as well as some toggle changes.

Simplify toggle:

```rust
/// Whether the entry is toggleable, and if so, whether it is currently toggled.
///
/// To make an element toggleable, simply add a `Toggle::Toggled(_)` and handle it's cases.
///
/// You can check if an element is toggleable with `.is_toggleable()`
///
/// Possible values:
/// - `Toggle::NotToggleable` - The entry is not toggleable
/// - `Toggle::Toggled(true)` - The entry is toggleable and toggled
/// - `Toggle::Toggled(false)` - The entry is toggleable and not toggled
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub enum Toggle {
    NotToggleable,
    Toggled(bool),
}
```

Adds helper functions to easily get the toggle and toggleable states:

```rust
impl Toggle {
    /// Returns true if the entry is toggled (or is not toggleable.)
    ///
    /// As element that isn't toggleable is always "expanded" or "enabled"
    /// returning true in that case makes sense.
    pub fn is_toggled(&self) -> bool {
        match self {
            Self::Toggled(false) => false,
            _ => true,
        }
    }

    pub fn is_toggleable(&self) -> bool {
        match self {
            Self::Toggled(_) => true,
            _ => false,
        }
    }
}
```

Pulls `disclosure_control` out of components and creates a common def:

```rust
pub fn disclosure_control<V: 'static>(toggle: Toggle) -> impl Component<V> {
    match (toggle.is_toggleable(), toggle.is_toggled()) {
        (false, _) => div(),
        (_, true) => div().child(
            IconElement::new(Icon::ChevronDown)
                .color(IconColor::Muted)
                .size(IconSize::Small),
        ),
        (_, false) => div().child(
            IconElement::new(Icon::ChevronRight)
                .color(IconColor::Muted)
                .size(IconSize::Small),
        ),
    }
}
```

disclosure_control will likely get pulled into it's own component in the
future instead of being in toggle.

Release Notes:

- N/A

This fixes a tiny UX bug where the tooltip would appear to move if you
hovered over an element, then moved your mouse out and back within
500ms.

The fix is to retain the task, so we can drop it to cancel it when the
mouse leaves.

Also changes the time we construct the tooltip to the time it first
shows.

Release Notes:

- Fixed an issue where markdown code blocks were not syntax-highlighted
in channel notes editors.

Co-Authored-By: Conrad Irwin <conrad@zed.dev>

Not as exciting as it sounds - Just starting to scaffold out some UI
docs and want to get feedback.

Release Notes:

- N/A

This PR removes the `components` module from `storybook2` as it was
dead, unreferenced code.

Release Notes:

- N/A

Co-Authored-By: Conrad Irwin <conrad@zed.dev>

This PR reorganizes the components in the `ui2` crate.

The distinction between "elements" and "components" is now gone, with
all of the reusable components living under `components/`.

The components that we built while prototyping but will eventually live
in other crates currently reside in the `to_extract/` module.

Release Notes:

- N/A

This PR adds support for deriving `Serialize` and `Deserialize` on the
refinement type generated by `#[derive(Refineable)]`.

Release Notes:

- N/A

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

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

r-a now has 2 different types of diagnostics: 
* "disk-based" ones that come from `cargo check` and related, that emit
`project::Event::DiskBasedDiagnosticsStarted` and
`DiskBasedDiagnosticsFinished`
* "flycheck" diagnostics from r-a itself, that it tries to dynamically
apply to every buffer open, that come with `DiagnosticsUpdated` event.

Latter diagnostics update frequently, on every file close and open, but
`diagnostics.rs` logic had never polled for new diagnostics after
registering the `DiagnosticsUpdated` event, so the only way we could
have newer diagnostics was to re-open the whole panel.
The PR fixes that, and also adds more debug logging to the module.
The logic of the fix looks very familiar to previous related fix:
https://github.com/zed-industries/zed/pull/3128

One notable thing after the fix: "flycheck" diagnostics stay forever if
the diagnostics panel is opened: excerpts in that panel do not allow the
buffer to get dropped (hence, closed in terms of r-a) and get the
updated, zero diagnostics.
If the diagnostics panel is opened and closed multiple times, those
errors gradually disappear.

Release Notes:

- Fixed diagnostics panel not refreshing its contents properly

Co-Authored-By: Julia <julia@zed.dev>

This PR removes the `Default` impl for `ThemeColors`.

Since we need default light and dark variants for `ThemeColors`, we
can't use a single `Default` impl.

Release Notes:

- N/A

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

Co-authored-by: Marshall <marshall@zed.dev>

Co-Authored-By: Marshall <marshall@zed.dev>
Co-Authored-By: Nathan <nathan@zed.dev>

Co-Authored-By: Julia <julia@zed.dev>