Process deleting projects as background task

[jayanth-kumar-morem]

1. Fix Default Filtering in ProjectFilterSet:

   • Modified the ProjectFilterSet to include is_marked_for_deletion in the default filtering when is_archived is not provided.
   • This ensures that projects marked for deletion are excluded from default views.

2. Migration for is_marked_for_deletion:

   • Added a migration (0052_project_is_marked_for_deletion.py) to introduce the is_marked_for_deletion field in the Project model.

3. Updated Project Model:

   • Added is_marked_for_deletion field to the Project model with a default value of False.

4. Modified ProjectListView to Exclude Marked Projects:

   • Modified the get_queryset method in ProjectListView to only fetch projects with is_marked_for_deletion=False.

5. Introduced mark_for_deletion Method:

   • Added a mark_for_deletion method in the Project model to set the is_marked_for_deletion flag and save the model.

6. Changed delete Method in Project Model:

   • Renamed the delete method to delete_action in the Project model to avoid conflicts.
   • Introduced a new delete method that marks the project for deletion and enqueues a background deletion task.

7. Background Deletion Task:

   • Created a background deletion task using django_rq to handle project deletion asynchronously.
   • Checks if the project is still marked for deletion before proceeding.
   • If an error occurs during deletion, updates project status and logs an error.

8. Updated ProjectActionView Success Message:

   • Modified the success message in ProjectActionView for the "delete" action to provide a more informative message based on the count.

Fixes: #1002

[pombredanne]

This is a good approach and well explained... it is likely missing not much to get this merged... @jayanth-kumar-morem do you mind looking into some of the comments?