Update script to clean inactive workspaces

[FelixMalfait]

We had built a script to clean inactive workspaces StartCleanInactiveWorkspacesCronCommand

Looking at object updates is not the right criteria because it can be performed automatically, for example if I connect a gmail account then it will look like the account is active when it's not.

Instead we should use the analytics data as a source of truth, and send a first warning email if there's been no activity for 2 weeks. Then delete it the third week if there still isn't any activity. Of cours paying workspace shouldn't be deleted even if they're inactive.