Feature soft delete forum messages

[felipecalvo]

:dart: Goal

Let forum messages be soft deleted.

:memo: Details

The following deletion motives are introduced:

• self_delete, intended for users who want to delete their own message;
• inappropriate_content,
• shares_correct_solution and
• discloses_personal_information, all three intended for moderators

Besides the deletion motive, we will also be persisting who deleted the message (deleted_by) and when (deleted_at)

[felipecalvo]

We should update this, right?

https://github.com/mumuki/mumuki-domain/blob/102ff99d2d9a3652ea9bb9cba7ae4c819396cdc4/app/models/message.rb#L14

There won't be true destroys anymore.

Edit: solved on a later commit.

[felipecalvo]

Alright, it's finally done. You might want to quickly check the last four commits, but it's in line with what we talked earlier.