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.

context/EditorContext.ts

@@ -1,10 +1,10 @@
-import {createContext} from "react";
+import {Context, createContext} from "react";
 import {Editor} from "@tiptap/core";
 
 export interface EditorContextProps {
     editor: Editor | null
 }
 
-export const EditorContext = createContext<EditorContextProps>({
+export const EditorContext: Context<EditorContextProps> = createContext<EditorContextProps>({
     editor: null
 });