Closes#48917
## Summary
- Stop sending `context.only` for generic `textDocument/codeAction`
requests.
- Keep explicit kind filtered requests unchanged.
- Add regression coverage for generic code action requests so actions
like `source.addTest` remain visible.
## Root Cause
`GetCodeActions::to_lsp` populated `context.only` even when the caller
requested all code actions (`kinds == None`). That turned the normal
code actions menu into a filtered request. With `gopls`, this filtered
out `source.addTest`, so `Add test for ...` never appeared.
## Verification
- `cargo fmt --all -- --check`
- `./script/clippy -p project`
- `cargo nextest run -p project --no-fail-fast --no-tests=warn`
- `cargo test -p editor
editor_tests::test_organize_imports_manual_trigger -- --exact`
- `cargo test -p editor
editor_tests::test_context_menus_hide_hover_popover -- --exact`
## Manual Testing
- Repro'd the protocol level behavior against `gopls`: unfiltered
requests return `source.addTest`, filtered requests excluding it do not.
- Opened `zed_guild/testing_projects/act/pkg/artifactcache/handler.go`
- Triggered `Show Code Actions` on `StartHandler`
- Confirmed `Add test for StartHandler` appears
Release Notes:
- Fixed Go `gopls` code actions so `Add test for ...` appears in the
generic code actions menu.
Co-authored-by: Kirill Bulatov <kirill@zed.dev>
