feat(highlight): migrate to tree-house with Helix queries

Replace tree-sitter-highlight dep with tree-house crate from Helix
editor. Add ropey dependency required by tree-house.

Reorganize query files from Helix's runtime/queries/ for all 14
supported languages:
- bash, c, css, go, html, javascript, json, markdown, nix, python,
  rust, toml, typescript, yaml
- Include ecma, _javascript, _typescript base dirs for JS/TS inheritance
- Copy highlights.scm, injections.scm, locals.scm where available

This commit establishes the foundation; highlight.rs implementation
will follow in subsequent commits.

queries/rust/locals.scm

@@ -0,0 +1,28 @@
+; Scopes
+
+[
+  (function_item)
+  (struct_item)
+  (enum_item)
+  (union_item)
+  (type_item)
+  (trait_item)
+  (impl_item)
+  (closure_expression)
+  (block)
+] @local.scope
+
+; Definitions
+
+(function_item
+  (parameters
+    (parameter
+      pattern: (identifier) @local.definition.variable.parameter)))
+
+(closure_parameters (identifier) @local.definition.variable.parameter)
+
+; References
+(identifier) @local.reference
+; lifetimes / labels
+(lifetime (identifier) @label)
+(label (identifier) @label)