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/cookies.ts

@@ -0,0 +1,33 @@
+export function getCookie(name: string): string | null {
+    const nameEQ: string = `${name}=`;
+    const allCookies: string[] = document.cookie.split(';');
+    for (let i: number = 0; i < allCookies.length; i++) {
+        let cookie: string = allCookies[i];
+        while (cookie.charAt(0) === ' ') cookie = cookie.substring(1, cookie.length);
+        if (cookie.indexOf(nameEQ) === 0) return cookie.substring(nameEQ.length, cookie.length);
+    }
+    return null;
+}
+
+export function setCookie(name: string, value: string, days: number): void {
+    const date: Date = new Date();
+    date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
+    const expires: string = `expires=${date.toUTCString()}`;
+    let domain: string = '';
+    if (!/localhost|127\.0\.0\.1/.test(window.location.hostname)) {
+        domain = `domain=${window.location.hostname};`;
+    }
+    const secure: string = 'Secure;';
+    const sameSite: string = 'SameSite=Strict;';
+    document.cookie = `${name}=${value}; ${expires}; ${domain} path=/; ${secure} ${sameSite}`;
+}
+
+export function removeCookie(name: string): void {
+    let domain: string = '';
+    if (!/localhost|127\.0\.0\.1/.test(window.location.hostname)) {
+        domain = `domain=${window.location.hostname};`;
+    }
+    const secure: string = 'Secure;';
+    const sameSite: string = 'SameSite=Strict;';
+    document.cookie = `${name}=; expires=Thu, 01 Jan 1970 00:00:00 GMT; ${domain} path=/; ${secure} ${sameSite}`;
+}