Refactor blog module and remove blog-related functionality

- Removed blog router and associated API endpoints.
- Deleted blog persistence functions and related query parameters.
- Removed blog schemas and models from the codebase.
- Introduced common crate for shared types, including DateTimeWithTimeZoneWrapper.
- Added Thought and Follow models with corresponding migrations.
- Updated dependencies in Cargo.toml files to reflect changes.
- Adjusted tests to remove references to the blog module.

thoughts-backend/tests/app/persistence/blog.rs

@@ -1,22 +0,0 @@
-use sea_orm::{DatabaseConnection, Unchanged};
-
-use app::persistence::blog::create_blog;
-use models::domains::blog;
-use models::params::blog::CreateBlogParams;
-
-pub(super) async fn test_blog(db: &DatabaseConnection) {
-    let params = CreateBlogParams {
-        author_id: 1,
-        title: "title".to_string(),
-        content: "test".to_string(),
-    };
-
-    let blog = create_blog(db, params).await.expect("Create blog failed!");
-    let expected = blog::ActiveModel {
-        id: Unchanged(1),
-        author_id: Unchanged(1),
-        title: Unchanged("title".to_owned()),
-        content: Unchanged("test".to_owned()),
-    };
-    assert_eq!(blog, expected);
-}

thoughts-backend/tests/app/persistence/mod.rs

@@ -1,9 +1,7 @@
 use utils::testing::setup_test_db;
 
-mod blog;
 mod user;
 
-use blog::test_blog;
 use user::test_user;
 
 #[tokio::test]
@@ -14,13 +12,3 @@ async fn user_main() {
 
     test_user(&db).await;
 }
-
-#[tokio::test]
-async fn blog_main() {
-    let db = setup_test_db("sqlite::memory:")
-        .await
-        .expect("Set up db failed!");
-
-    test_user(&db).await;
-    test_blog(&db).await;
-}