Suggestion: Restructure the permission tree on commands usage.

[Sasiko]

There are permission inconsistency for different mod mail commands. Taku pointed out that you need manage channel permission to use ?contact command
while you only need manage message permission to use subcommands of alias/snippets and more.

The permission are also undocumented from wikis which can lead to confusion of who can use what commands or not. Because as above mention only specific commands works for specific permission granted for each role.

Suggestion: Rather then having mod mail check what specific permission a role has, let us add role ID as it adds far more flexibility and let us fully customize the commands permission where we can choose what commands role id can use.

We can also have presets of command permission based on 3 profiles.
Admin, moderator and helper.
These 3 have already have assigned to specific amount of commands of what they are allowed to use incase user dont want to individually enable specific commands, one at the time.