RC4 optimized

1. Automate Community
2. Security

Encrypt/Decrypt any small file using RC4 algorithm.

Your password can (and should) contain emojis and other Unicode chars. Android's password keyboard doesn't accept emojis nor lines, so I had to set a keyboard that shows the written chars. If you want your password to be hidden while typing, you can't use emojis and other characters (I know, it's ridiculous)

I did a lot of benchmarks with different configurations and this is very likely to be THE fastest implementation in AM (it can be faster with loop unrolling, but that requires too many blocks).

Original by Qwerty Cat: llamalab.com/automate/community/flows/25728