feat(moderation): post purge log

[Ushie]

🐞 Issue

Currently, the bot doesn't post a log when a purge command is run, and there's no history of the purged messages

❗ Solution

Post a log of the action and an attachment of the purged content for reference purposes

❓ Motivation

Consistency with other moderative actions and ability to reference content that was purged

[Ushie]

@oSumAtrIX I'm going to start with this, should I keep anything in mind?

[oSumAtrIX]

The attachment might not be necessary, but if still wanted, should be added as an file attachment to the log otherwise it'll it 2000 character limit possibly.

[Ushie]

Yep, I meant that type of attachment👍