Bridge message cleanup does not remove empty messages with :emojis:

[S-S-X]

Cleanup was improved a bit here: #35

Most part works, it does remove test emojis and it does throws messages not containing meaningful words to /dev/null.

However, if simple emoji is present in message then that message gets through even while emoji is not visible in mintest chat.
That is emojis which are not removed by https://github.com/minetest-beerchat/beerchat/blob/9b58f90ba0dc61563a6b7188bb86131dc4b8cbd6/plugin/cleaner.lua#L9-L15

So it seems like those are actually getting through that check and simply not rendered by minetest chat or they're converted and sent as unicode emojis which lua pattern matcher recognizes as something not in [%c%p%s].

[S-S-X]

Confirmed conversion happening at some stage, probably at Discord. Sending :smiley: from IRC will send text exactly as written.
This is good because what should be cleaned up is just things that minetest cannot handle which is emojis, so what is needed is semi reliable way to check for unicode emojis.