Fix: performance issues

[mateki0]

In this PR I add some limitations to the number of rendered emojis to prevent rendering emojis out of view.

Previously when we open a keyboard and it was on first category even emojis from the last one were rendered. That was causing problems not only in the keyboard itself but also on the screen where it was used. There's still a small delay on changing category but it's significantly reduced. However it may be caused by development build so I decided to go with it for now and search for more improvements in the future if needed.

Edit: as you can see from commits I was forced to also fix them in this PR to not break workflows on main after merging this one

closes #148

[jan-kozinski]

good job 👍 tested on iPhone 15 simulator and Pixel 3a emulator, you can feel the difference on both. Looks much smoother than it used to

[jakex7]

Nice! There is noticeably better performance. Unfortunately, it introduces an issue with the scroll indicator (screen recording below). Despite this, I think we could merge it and then think about a solution.

RPReplay_Final1705348348.MP4

[mateki0]

Nice! There is noticeably better performance. Unfortunately, it introduces an issue with the scroll indicator (screen recording below). Despite this, I think we could merge it and then think about a solution.

RPReplay_Final1705348348.MP4

I saw that too, but I didn't find a nice way to maintain a static size of scrollbar. However i thought that the overall performance is more important than scrollbar which is usually hidden in most applications. Anyway thanks for checks we can merge it (I'm not able to do so)