feat: add interactions per server

[thijsfranck]

We should set up interactions to retrieve statistics per server. Statistics include:

• (key)word frequency (top 10 of up to 100 most recent messages)
• similarity score (up to 100 most recent messages)
• sentiment score (up to 100 most recent messages)

Interactions should include:

• slash command
• right click context menu

Statistics should be posted as a private message to the user in the current server, or as a DM if outside of a channel context.

This action should only be available to privileged users.

[elfkuzco]

Um, if we are calculating a similarity score, that means there should be a message to be compared against? If this statistics were to be fetched for a server, which message would be used as the comparison message?

@isaa-ctaylor @thijsfranck