editor: Honor lsp_results_location in the cmd-click references fallback (#61187)

Follow-up to #59838, implementing what was discussed at the end of
#59829: cmd-click navigation now respects `lsp_results_location` when
go-to-definition falls back to find-all-references (invited in
https://github.com/zed-industries/zed/issues/59829#issuecomment-4989966493:
"It would! Feel free to hook that up if you'd like to!").

## Problem

Cmd-clicking a symbol's definition falls back to find-all-references,
but the results always open in a multibuffer even with
`"lsp_results_location": "picker"`. The hover-link click path calls the
editor navigation methods directly, so the action handlers registered by
`lsp_locations` never get a chance to intercept.

## Solution

- `handle_click_hovered_link`'s fallback now dispatches the
`FindAllReferences` action (with `open_results_in: None`, deferring to
the global setting) instead of calling the method, so the
`lsp_locations` handler can intercept it, or propagate to the editor's
built-in handler when the setting is `multi_buffer`, preserving today's
behavior exactly.
- The plain cmd-click arm of `cmd_click_reveal_task` now runs the
definition query via `go_to_definition_of_kind` (no internal references
fallback) instead of `go_to_definition`, so the click path has a single
fallback decision point: the dispatching one. Without this, the method's
baked-in fallback opened a multibuffer before the dispatch could run.
- `go_to_definition_of_kind` visibility widened to `pub(crate)` for the
call from `hover_links.rs`.

Shift/alt click variants (type definition, splits) are untouched.
Keyboard invocations were already intercepted and are unchanged.

## Testing

- New test `test_cmd_click_fallback_honors_lsp_results_location` in
`lsp_locations`, following the module's existing test patterns: fake LSP
returning no definition and two references, `lsp_results_location:
picker`, simulated cmd-click at the cursor's pixel position, asserts the
picker opens. The test fails without this change.
- `cargo nextest run -p lsp_locations`: 6/6.
- `cargo nextest run -p editor -E 'test(hover) or test(fallback) or
test(go_to_definition) or test(references)'`: 54/54.
- `cargo fmt` and `./script/clippy` clean.
- Verified manually in a release build: with the setting on,
cmd-clicking a definition opens the picker; with it off, behavior is
unchanged.

Per the contributing guidelines' note on AI assistance: this change was
developed with heavy AI assistance (Claude Code). I have reviewed and
understand the full diff and the reasoning behind each hunk, and I'm the
one answering review feedback.

Release Notes:

- Fixed cmd-click go-to-definition falling back to a references
multibuffer even when `lsp_results_location` is set to `picker`.