fix(language-service): fix calculation of pipe spans (#35986)

This commit accomplishes two tasks:

- Fixes the span of queried pipes to only be applied on pipe names
- By consequence, fixes how pipes are located in arguments (previously,
  pipes with arguments could not be found because the span of a pipe
  uses a relative span, while the template position is absolute)

The screenshots attached to the PR for this commit demonstrate the
change.

Closes https://github.com/angular/vscode-ng-language-service/issues/677

PR Close #35986

packages/language-service/test/hover_spec.ts

@@ -138,6 +138,19 @@ describe('hover', () => {
       expect(toText(displayParts)).toBe('(property) TemplateReference.heroes: Hero[]');
     });
 
+    it('should work for pipes', () => {
+      mockHost.override(TEST_TEMPLATE, `
+        <p>The hero's birthday is {{birthday | «date»: "MM/dd/yy"}}</p>`);
+      const marker = mockHost.getReferenceMarkerFor(TEST_TEMPLATE, 'date');
+      const quickInfo = ngLS.getQuickInfoAtPosition(TEST_TEMPLATE, marker.start);
+      expect(quickInfo).toBeTruthy();
+      const {textSpan, displayParts} = quickInfo !;
+      expect(textSpan).toEqual(marker);
+      expect(toText(displayParts))
+          .toBe(
+              '(pipe) date: (value: any, format?: string | undefined, timezone?: string | undefined, locale?: string | undefined) => string | null');
+    });
+
     it('should work for the $any() cast function', () => {
       const content = mockHost.override(TEST_TEMPLATE, '<div>{{$any(title)}}</div>');
       const position = content.indexOf('$any');