Refactor and enhance type safety across various modules

- Updated function parameters and return types in `page-preview.ts`, `pdf-decrypt.ts`, and `pymupdf-loader.ts` for improved type safety.
- Introduced type definitions for `CpdfInstance`, `PyMuPDFInstance`, and other related types to ensure better type checking.
- Enhanced error handling in `sanitize.ts` by creating a utility function for error messages.
- Removed unnecessary type assertions and improved type inference in `editor.ts`, `serialization.ts`, and `tools.test.ts`.
- Added type definitions for markdown-it plugins to improve compatibility and type safety.
- Enforced stricter TypeScript settings by enabling `noImplicitAny` in `tsconfig.json`.
- Cleaned up test files by refining type assertions and ensuring consistency in type usage.

src/js/logic/table-of-contents.ts

@@ -36,15 +36,6 @@ const backToToolsBtn = document.getElementById(
   'back-to-tools'
 ) as HTMLButtonElement;
 
-interface GenerateTOCMessage {
-  command: 'generate-toc';
-  pdfData: ArrayBuffer;
-  title: string;
-  fontSize: number;
-  fontFamily: number;
-  addBookmark: boolean;
-}
-
 interface TOCSuccessResponse {
   status: 'success';
   pdfBytes: ArrayBuffer;