refactor: remove HTML report export and implement PDF export options in PDF comparison tool

- Deleted the exportCompareHtmlReport function and its related imports.
- Introduced a dropdown menu for exporting comparison results as PDFs with multiple modes (split, alternating, left, right).
- Updated the comparison logic to utilize caching for page models and comparison results.
- Refactored rendering functions to improve code organization and maintainability.
- Enhanced UI elements for better user experience during PDF export.

src/js/types/compare-pdfs-type.ts

@@ -1 +1,9 @@
-export type { CompareState } from '../compare/types.ts';
+export type {
+  CompareState,
+  ComparePdfExportMode,
+  RenderedPage,
+  ComparisonPageLoad,
+  DiffFocusRegion,
+  CompareCaches,
+  CompareRenderContext,
+} from '../compare/types.ts';