Add Blank Screen, Rabbit-Labs and Pwnagotchi packs

[the1anonlypr3]

i am become the anims
hope this works, i literally did most of it manually (but verified with the py script, no errors)

[the1anonlypr3]

also added pwnagotchi anims :D

[the1anonlypr3]

added pfps to the pwnagotchi anim pack :)

[Willy-JL]

i feel like the blank screen asset packs could go together, so just call it "Blank Screen" and it would install both Blank Screen - White and Blank Screen - Black.

top-level pack names should be lowercase letters, numbers and dashes only, and not contain author info (unless theres multiple versions of same theme of asset pack by multiple authors or some other situation like that) since thats shown on website with metadata

finally previews should be taken with qflipper screenshot button for still images, and for videos/gifs would ideally be the same kind of thing but recorded in some other way (basically cropping to just the content of the frame, not the external border that qflipper puts around it. kuronons usually has them spot on, not sure how he records his, or if the animation manager can render them too, dunno

ill get it all sorted )