feat(favourites): add, edit, import and export of favourites

[nijuyonkadesu]

Is your feature request related to a problem? Please describe. Currently, there is only one way to save fav images, ie, to download the image itlsef to 'Pictures' directory. Having and exporting urls would be nice? (✿◡‿◡)

Describe the solution you'd like

1. Add
2. Edit
3. Import
4. Export

Describe alternatives you've considered Minor additions to above feature:

• Do we need a batch download on these URLs ?
• A toast with a small img thumbnail? (coz, the image selection mechanism is not super accurate in SAO)

maybe, just maybe ~ navigate to another carousel view (vertical), but show only the favourited urls? with a heart icon (spam it) with a delete icon (ofc) + undo snack bar

[nijuyonkadesu]

this and #17

[nijuyonkadesu]

plan is to simply store them as list

• it would be nice to group favourites under various categories
• map with emoji? #21

^^^^ will plan out when window manager thingy is figured out

[nijuyonkadesu]

auto categorize with ML model? ehhhhhhh

[nijuyonkadesu]

actually I want SAO to be the alternate repository for stickers that work on all applications ~

[nijuyonkadesu]