✨ Add combo hashtag rule

[foysalit]

This PR adds a way for us to takedown accounts that post content with very bad hashtags.
This introduces the need for 2 new sets potentially-bad-hashtags and potentially-bad-hashtag-combos.

However, ideally, these would be nested arrays so that each potentially-bad-hashtags item would have nested items of potentially-bad-hashtag-combos so that we could build hierarchies like

'test' -> ['check', 'now']
'call' - > ['me', 'her']

• if a post has #test and #check rule will be activated but 'test' and 'me' won't

[bnewbold]

I would make this a separate new rule instead of bundling with the current rule.

Jumping straight to takedown is also aggressive. In an urgent situation we can at least start with !warn or !hide on the overall account. Cleaning up mistakes is very laborious, and this kind of rule in particular is going to have a bunch of false-positives.