Update Notification API Endpoints and Documentation

- Changed the endpoint for marking notifications as seen to improve clarity and consistency in the API structure.
- Updated the endpoint for marking all notifications as seen to a more descriptive path.
- Reflected these changes in the Swagger documentation, ensuring accurate representation of the updated API endpoints for consumers.

cmd/web/docs/swagger.json

@@ -5523,7 +5523,7 @@
                 }
             }
         },
-        "/api/v1/notifications/all-seen/{user_id}": {
+        "/api/v1/notifications/mark": {
             "get": {
                 "security": [
                     {
@@ -5572,7 +5572,7 @@
                 }
             }
         },
-        "/api/v1/notifications/mark-seen/{id}": {
+        "/api/v1/notifications/mark/{id}": {
             "get": {
                 "security": [
                     {