feat(language-service): support multiple symbol definitions (#34782)

In Angular, symbol can have multiple definitions (e.g. a two-way
binding). This commit adds support for for multiple definitions for a
queried location in a template.

PR Close #34782

packages/language-service/src/expressions.ts

@@ -148,8 +148,14 @@ export function getExpressionSymbol(
     },
     visitPropertyWrite(ast) {
       const receiverType = getType(ast.receiver);
+      const {start} = ast.span;
       symbol = receiverType && receiverType.members().get(ast.name);
-      span = ast.span;
+      // A PropertyWrite span includes both the LHS (name) and the RHS (value) of the write. In this
+      // visit, only the name is relevant.
+      //   prop=$event
+      //   ^^^^        name
+      //        ^^^^^^ value; visited separately as a nested AST
+      span = {start, end: start + ast.name.length};
     },
     visitQuote(ast) {},
     visitSafeMethodCall(ast) {