Remove unused components and models for improved maintainability

- Deleted redundant components (`AddActionButton`, `AlertBox`, `AlertStack`, `BackButton`, `CancelButton`, and `CollapsableArea`) and related files.
- Removed unused models (`Book`, `BookSerie`, `BookTables`, `Character`, and `Chapter`) to reduce codebase clutter.
- Updated project structure and references to reflect these removals.

lib/utils/validation.ts

@@ -0,0 +1,4 @@
+export function verifyInput(input: string): boolean {
+    const pattern: RegExp = new RegExp('(<.*?>)|(&.*?;)|({.*?})', 'gmi');
+    return pattern.test(input);
+}