Add reports support

[bpavuk]

Fakey should be clean place - if users see porn, cruel kills, scenes of using narcotics, recipes of how to make drugs at home, spam, how to make your penis longer, etc., they should have a place to report about that.

Tech task

• Users should have the /posts/{id}/report and /users/{id}/report endpoints in their hands.
• Those endpoints should receive JSON with 2 elements: reason and description.
• After receiving, they put report to reports registry (it can be just simple SQL table, but after all, it should contain all reports).
• Next, users with special access (moderators) should rate the report - is it false positive, or helpful
• If false positive, report is closed
• If helpful, moderator can choose the punishment - from post deletion with notification to permaban by email
• Only developers can approve permabans