Moderation 3: Moderation Frontend

[ailisp]

Blocked by #541

Acceptance Criteria

• Fork and use this menu component to report a post, which stores the reporting and hiding information to SocialDB.
• The exact format of reporting and hiding information is different from original menu component and should be documented in #541. Note that the difference between reporting and hiding is that, reporting if approved by moderators, will be apply globally to DevHub. Hiding is a local preference that's effective only to current account.
• Fork the Moderator interface widget for moderators to see those reports and store moderate decision to SocialDB. The format of SocialDB decision is also different from the original Moderator interface widget and should be documented in #541
• For applying delete reported posts, it should be done in #541 so take the final indexer result given by #541 to replace currently devhub_vXX's posts_with_latest_snapshot
• For hiding a post, the frontend needs to futher apply user's hiding settings, created by the menu component described above and stored in SocialDB
• Delete reported posts and hide posts should apply to feed, search result, community feed and post detail page. For feed, search result and community feed, simply not show deleted/hidden posts. For post detail page, indicate the post is deleted or hidden.