feat: Implement blog and blog post models, routes, and services

- Added Blog and BlogPost models with necessary fields and relationships.
- Created blogRouter for handling blog-related API endpoints including CRUD operations.
- Developed BlogService for business logic related to blogs and posts, including sharing functionality.
- Implemented API client methods for frontend to interact with blog-related endpoints.
- Added internationalization support for blog-related text in English and German.
- Created Vue components for blog editing, listing, and viewing, including a rich text editor for post content.
- Enhanced user experience with form validations and dynamic visibility settings based on user input.

backend/models/index.js

@@ -34,6 +34,8 @@ import MessageHistory from './forum/message_history.js';
 import MessageImage from './forum/message_image.js';
 import ForumForumPermission from './forum/forum_forum_permission.js';
 import Friendship from './community/friendship.js';
+import Blog from './community/blog.js';
+import BlogPost from './community/blog_post.js';
 
 import FalukantUser from './falukant/data/user.js';
 import RegionType from './falukant/type/region.js';
@@ -140,6 +142,8 @@ const models = {
   MessageHistory,
   MessageImage,
   Friendship,
+  Blog,
+  BlogPost,
 
   // Falukant core
   RegionType,