request: autopurge system

[favna]

Is your feature request related to a problem? Please describe.

There has been a request to add an auto purging system. Basically it would run on a schedule given a channel and a certain amount of messages and everytime the schedule is reached, the given amount of messages are deleted from the given channel.

Describe the solution you'd like

autopurge command that has a setup similar to selfmod mode commands

• autopurge enable/disablee to enable/disable the system
• autopurge add <channelname> <inteval> [messageCount:number = 100] [filter:...string] to add a new auto purge rule. Filter is rest string as it should be able to match message content (case insensitive!). messageCount is optional and defaults to 100 messages to scan.
• autopurge show to show a list of autopurge rules, listed by ID with their channels, a timestamp to the next purge, the messages to be scanned and any filter that would be applied. Probably use RichDisplay here.
• autopurge remove <id> to remove a specific autopurge rule
• autopurge reset to remove all autopurge rules

Optional:

• autopurge edit <id> <channelname> <inteval> [messageCount:number = 100] [filter:...string] to edit an existing autopurge rule. Optional because people can also remove then re-add.

Describe alternatives you've considered

N.A.

Additional context

https://discordapp.com/channels/254360814063058944/382531782387695616/784560386875195463
https://discordapp.com/channels/254360814063058944/382531782387695616/784564902735642644

#140 in #suggestions