Prevent role hierarchy issues with infractions

[TizzySaurus]

Closes #1780.

log.warning is no longer called when an infraction/pardon fails due to the target being a Moderator+

I believe this is what @MarkKoz was after when they created their issue.

Not sure whether we want to still ping @Moderators if the pardon fails for this reason or not, but have left the ping there for now (can remove if requested).

[MarkKoz]

Did you test this first? It won't work because you're comparing role objects against IDs.

Also, do you think it would be scope creep to create a utility function for this role checking, since a similar pattern is being used elsewhere in the codebase?

[TizzySaurus]

After a long discussion on discord it was decided to simply prevent the error raised from using !starify on members above the bot in the role hierarchy by not allowing invocation on such members.

A summary of reason is basically that in the other cases we want to know something went wrong, because there shouldn't be an error in any other infractions due to the user being staff (we can successfully mute etc. staff, including Moderators+, it's only starify we can't as it changes nickname which is hierarchy dependant.)

Edit: just realised kicks and bans are also hierarchy dependant, so have added the same check to them.

[TizzySaurus]

After many hours dabbling with the tests I figured out how to fix them. Hopefully this should all now be ready to merge, just needs the reviews 👍

outdated

[jchristgit]

I like this. One minor nitpick. Feel free to ignore it completely.