Added feature where if a suffix is added to an emotes it will horizontally flip the emote

[nirajacharya2]

related feature #364

after creating this PR i noticed few problems:
lets say the mirror suffix is _M

• if an emote already exist that has _M at the end it mirrors it. it shouldn't do that
• if a user wants to upload an emote with _M letters at end 7tv shouldn't let them upload them or at least warn them and i think there might be more requests like this for examples :
  • invert colors
  • make it continuously rotate
  • turn it 90,180 ... degrees
    or even something like that we have natively in twitch like emote_BW makes black and white, emote_SG(probably zerowidth emote dose this) puts sunglasses etc. for that 7tv should reserve some suffix which might be annoying

[AnatoleAM]

This is not gonna be the way we implement this. For one, with the modifier token attached to the emote, it means any third party client will now only see text, which is double the amount of text pollution from how other providers have done similar, and from seeing their rollout, those features are rarely used after the initial week.

This would have to be significantly refined and provided with much more thought, a specification for third party implementation, and most likely require API integration allowing channels to turn this on or off.

[nirajacharya2]

with the modifier token attached to the emote, it means any third party client will now only see text

makes sense since chatterino and other moblile apps wont know its an emote. i should have thought of it.