Add dart lsp config and queries (#1250)

* Add language: dart

The setup requires that dart be in the users path, such as:
```
export PATH="$HOME/Android/flutter/bin/cache/dart-sdk/bin/:$PATH"
```

Refactor the dart highlights

* lang: dart: add indents and locals

* lang: dart: corrections to local scope

Co-authored-by: Blaž Hrastnik <blaz@mxxn.io>

1 files changed, 0 insertions, 0 deletions

diff --git a/helix-syntax/languages/tree-sitter-dart b/helix-syntax/languages/tree-sitter-dart
new file mode 160000
+Subproject 6a25376685d1d47968c2cef06d4db8d84a70025