[ty] Added support for "document highlights" language server feature. (#19515)

This PR adds support for the "document highlights" language server
feature.

This feature allows a client to highlight all instances of a selected
name within a document. Without this feature, editors perform
highlighting based on a simple text match. This adds semantic knowledge.

The implementation of this feature largely overlaps that of the
recently-added "references" feature. This PR refactors the existing
"references.rs" module, separating out the functionality and tests that
are specific to the other language feature into a "goto_references.rs"
module. The "references.rs" module now contains the functionality that
is common to "goto references", "document highlights" and "rename"
(which is not yet implemented).

As part of this PR, I also created a new `ReferenceTarget` type which is
similar to the existing `NavigationTarget` type but better suited for
references. This idea was suggested by @MichaReiser in [this code review
feedback](https://github.com/astral-sh/ruff/pull/19475#discussion_r2224061006)
from a previous PR. Notably, this new type contains a field that
specifies the "kind" of the reference (read, write or other). This
"kind" is needed for the document highlights feature.

Before: all textual instances of `foo` are highlighted
<img width="156" height="126" alt="Screenshot 2025-07-23 at 12 51 09 PM"
src="https://github.com/user-attachments/assets/37ccdb2f-d48a-473d-89d5-8e89cb6c394e"
/>

After: only semantic matches are highlighted
<img width="164" height="157" alt="Screenshot 2025-07-23 at 12 52 05 PM"
src="https://github.com/user-attachments/assets/2efadadd-4691-4815-af04-b031e74c81b7"
/>

---------

Co-authored-by: UnboundVariable <unbound@gmail.com>

crates/ty_wasm/src/lib.rs

@@ -15,10 +15,9 @@ use ruff_python_formatter::formatted_file;
 use ruff_source_file::{LineIndex, OneIndexed, SourceLocation};
 use ruff_text_size::{Ranged, TextSize};
 use ty_ide::{
-    MarkupKind, RangedValue, goto_declaration, goto_definition, goto_type_definition, hover,
-    inlay_hints, references,
+    MarkupKind, NavigationTargets, RangedValue, goto_declaration, goto_definition, goto_references,
+    goto_type_definition, hover, inlay_hints, signature_help,
 };
-use ty_ide::{NavigationTargets, signature_help};
 use ty_project::metadata::options::Options;
 use ty_project::metadata::value::ValueSource;
 use ty_project::watch::{ChangeEvent, ChangedKind, CreatedKind, DeletedKind};
@@ -338,14 +337,30 @@ impl Workspace {
 
         let offset = position.to_text_size(&source, &index, self.position_encoding)?;
 
-        let Some(targets) = references(&self.db, file_id.file, offset, true) else {
+        let Some(targets) = goto_references(&self.db, file_id.file, offset, true) else {
             return Ok(Vec::new());
         };
 
         Ok(targets
             .into_iter()
-            .flat_map(|target| {
-                map_targets_to_links(&self.db, target, &source, &index, self.position_encoding)
+            .map(|target| LocationLink {
+                path: target.file().path(&self.db).to_string(),
+                full_range: Range::from_file_range(
+                    &self.db,
+                    target.file_range(),
+                    self.position_encoding,
+                ),
+                selection_range: Some(Range::from_file_range(
+                    &self.db,
+                    target.file_range(),
+                    self.position_encoding,
+                )),
+                origin_selection_range: Some(Range::from_text_range(
+                    ruff_text_size::TextRange::new(offset, offset),
+                    &index,
+                    &source,
+                    self.position_encoding,
+                )),
             })
             .collect())
     }