feat: add gif picker using giphy api

[JuLi0n21]

• I have read and understood the contributing guidelines.

Pull Request has been tested on:

• Android
• iOS
• Browser (Chromium based)
• Browser (Firefox based)
• Browser (WebKit based)
• Desktop Linux
• Desktop Windows
• Desktop macOS

Implements #700
Tenor is dead, this is a replacement build using Giphy as the api
the code builds on top ##2137 and the changed file sending behavior from ItsKaa@3ca6d9c

now because giphy seems to be very pricey, a place in the chat / emoji configuration was added to input ur own apikey with a mini guide, this should be replaced if we use a commercial lisence (i have not read the tos if this is allowed) secondly caching infrasturce will defently be required to cut costs, currently the gif ui is hidden if no apikey is provided.

currently the rating is hardcoded to r if this should be editable/ changed pls say so

i was also looking for ideas to have favorite gifs in the same tab, wasnt sure how to best handle the persistent storage required

Screenshots:

[krille-chan]

I really appreciate your work and contribution. Unfortunately I'm concerned about the privacy impact of embedding giphy into our product. Yes it could be optional. However also the solution with the token is something I'm concerned because adding your own token is very complicated for normal users so this would only be useful for a very tiny fraction of users while it seems to be a quite complex feature which could easily break. According to the design philosophy of FluffyChat to keep everything very minimalistic (and therefore easy to maintain) I'm not sure that this fits into it. Also because there are several workarounds. Most keyboards on Android and the default iOS keyboard already have giphy embedded into it and it is quite easy to go to the giphy website and copy-paste them. So this is only a convenient feature for a very small fraction of the users.

Maybe a compromise: We make pasting images possible instead so for desktop users it becomes much easier to copy-paste gifs from the giphy website: #2840

[TheAnnoyingFruit]

Klipy is another option for gif api