Create a database method to apply a list of permissions to a list of repos

Created by: asdine

This method receives a list of repos and a list of permissions that need to be applied to both the user_permissions table and repo_permissions table.

• This method must completely replace old permissions with the new ones.
• It doesn't need to be atomic (i.e. can use batches in different transactions without the need to rollback everything)
• It must be idempotent (i.e. the workerutil package might call this method multiple times in case of errors)