Add Gif Picker and Reaction Autofill

[OneBigLotus]

I understand the incredibly strict memory and CPU budget for this application but having optional support for reactions and gifs on devices that can support it would be a game changer for the client. I appreciate all the work that's been put in thus far

[iProgramMC]

Reaction support is dependent on #81 being solved. So as long as emojis aren't implemented, neither will reactions.

GIF support will likely not be added as it requires more memory and CPU power than you might think.

From what I can tell, there are two options:

• decompress ALL the gif's frames in memory, which can take up hundreds of megabytes
• decompress each frame of the gif everytime the image loads, which takes up more CPU power

Additionally having constantly updating graphics is a task this project isn't really suited for.

[OneBigLotus]

I actually do have some experience with embedding gifs in python and it's definitely more memory usage or cpu resource than you would expect, that's why in the suggestion I mentioned it to be exclusively on devices that far surpass the system requirement. For emojis is that makes a lot of sense, but does that also apply to user uploaded emojis?

[iProgramMC]

Reactions wouldn't make a whole lot of sense unless you supported both standard unicode emoji and user-created emoji. Worth mentioning that user-created emoji are already supported in Discord Messenger.

[OneBigLotus]

That makes a lot of sense, a lot of them only show up as unicode on my client but that might be due to the fact that they're animated. I appreciate the insight!