feat(Parser): Add ThumbnailOverlayTitleView and PageIndicatorView classes (#1120)

Add two missing parser classes that were being JIT-generated at runtime:

- ThumbnailOverlayTitleView: Displays title/subtitle overlays on thumbnails
- PageIndicatorView: Tracks pagination state in carousels (indicator count and selected index)

These are encountered when parsing Mix/Playlist responses.

src/parser/classes/PageIndicatorView.ts

@@ -0,0 +1,15 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+
+export default class PageIndicatorView extends YTNode {
+  static type = 'PageIndicatorView';
+
+  public indicator_count: number;
+  public selected_index: number;
+
+  constructor(data: RawNode) {
+    super();
+    this.indicator_count = data.indicatorCount ?? 0;
+    this.selected_index = data.selectedIndex ?? 0;
+  }
+}

src/parser/classes/ThumbnailOverlayTitleView.ts

@@ -0,0 +1,15 @@
+import { YTNode } from '../helpers.js';
+import type { RawNode } from '../index.js';
+
+export default class ThumbnailOverlayTitleView extends YTNode {
+  static type = 'ThumbnailOverlayTitleView';
+
+  public title: string;
+  public subtitle: string;
+
+  constructor(data: RawNode) {
+    super();
+    this.title = data.title?.content ?? '';
+    this.subtitle = data.subtitle?.content ?? '';
+  }
+}