refactor(language-service): Remove redudant 'TemplateInfo' type (#32250)

The TemplateInfo type is an extension of AstResult, but it is not
necessary at all. Instead, improve the current interface for AstResult
by removing all optional fileds and include the TemplateSource in
AstResult instead.

PR Close #32250

packages/language-service/src/definitions.ts

@@ -7,7 +7,7 @@
  */
 
 import * as ts from 'typescript'; // used as value and is provided at runtime
-import {TemplateInfo} from './common';
+import {AstResult} from './common';
 import {locateSymbol} from './locate_symbol';
 import {Span} from './types';
 
@@ -23,9 +23,15 @@ function ngSpanToTsTextSpan(span: Span): ts.TextSpan {
   };
 }
 
-export function getDefinitionAndBoundSpan(info: TemplateInfo): ts.DefinitionInfoAndBoundSpan|
-    undefined {
-  const symbolInfo = locateSymbol(info);
+/**
+ * Traverse the template AST and look for the symbol located at `position`, then
+ * return its definition and span of bound text.
+ * @param info
+ * @param position
+ */
+export function getDefinitionAndBoundSpan(
+    info: AstResult, position: number): ts.DefinitionInfoAndBoundSpan|undefined {
+  const symbolInfo = locateSymbol(info, position);
   if (!symbolInfo) {
     return;
   }