Purpose:
In a scope of this task we need to rebuild database structure, remove unused columns, reorganize tables.

Approach

• Write script to edit database structure
       - Remove tables: providers, packages, resources, titles 
       - Add foreign key "credentials_id" for table tags 

• Write script to migrate data

• Implement logic to retrieve objects by TagFilter from tags table. (remove joiners)

• Delete all code related old tables (f.e. PackageRepository, ResourceRepository). Remove code duplications

• Make sure unit tests are passed successful