Add configurable heat measurement

[emmiegit]

An experimental feature to calculate the "heat" of a user through various weights on the stream of inputs: typing events, message length, number of newlines, embeds, attachments, links, having a picture or video, speed of messages sent, etc. This final heat score could then have enforcement levels set to automatically flag, then mute heated users.

This issue only calls for adding a way to measure heat values to experiment with possible weights. As we see the possible viability or lack of automatic enforcement, we will create new issues then.