feat(dart): improve locals query (#4922)

queries/dart/locals.scm

@@ -1,8 +1,34 @@
+;; Definitions
+
+(function_signature
+  name: (identifier) @definition.function)
+
+(formal_parameter
+  name: (identifier) @definition.parameter)
+
+(initialized_variable_definition
+  name: (identifier) @definition.var)
+
+(initialized_identifier
+  (identifier) @definition.var)
+
+(static_final_declaration
+  (identifier) @definition.var)
+
+;; References
+
+(identifier) @reference
+
+;; Scopes
+
 (class_definition
- body: (_) @scope)
-
- (block) @scope
-
- (try_statement) @scope
- (catch_clause) @scope
- (finally_clause) @scope
+  body: (_) @scope)
+[
+ (block)
+ (if_statement)
+ (for_statement)
+ (while_statement)
+ (try_statement)
+ (catch_clause)
+ (finally_clause)
+] @scope