fix(compiler): ensure that event handlers have the correct source spans (#28055)

When template bindings are being parsed the event handlers
were receiving a source span that included the whole attribute.

Now they get a span that is focussed on the handler itself.

PR Close #28055

packages/compiler/src/expression_parser/ast.ts

@@ -698,7 +698,8 @@ export class ParsedEvent {
   // Animation events have a phase
   constructor(
       public name: string, public targetOrPhase: string, public type: ParsedEventType,
-      public handler: AST, public sourceSpan: ParseSourceSpan) {}
+      public handler: AST, public sourceSpan: ParseSourceSpan,
+      public handlerSpan: ParseSourceSpan) {}
 }
 
 export class ParsedVariable {