[FEATURE] Add Message Purge Command

[tomlin7]

Add Message Purge Command

add a message purging command, to purge messages in chat.

The commands can be formatted as follows:

• purge @user

purges n messages of the mentioned user,

• purge

purges n messages in chat.

Purpose

Purge command is one of the fundamental commands which should be in a moderation bot. It helps to avoid spamming, removing inappropriate content, trolls.