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/api/src/routers/mod.rs

@@ -1,11 +1,9 @@
 use axum::Router;
 
-pub mod blog;
 pub mod root;
 pub mod user;
 
 use app::state::AppState;
-use blog::create_blog_router;
 use root::create_root_router;
 use user::create_user_router;
 
@@ -13,6 +11,5 @@ pub fn create_router(state: AppState) -> Router {
     Router::new()
         .merge(create_root_router())
         .nest("/users", create_user_router())
-        .nest("/blogs", create_blog_router())
         .with_state(state)
 }