Move the creation of the drawable.xml to Android studio

[Kaiserdragon2]

this moves the creation of the drawable.xml and the copy of the appfilter file to Android studio.
Also it adds an option to the preparerelease script to allow keeping the the current new drawables and add new icons to it.
This allows the script to be run in between releases without the need to revert these changes to have all new icons in new.

usage: preparerelease.py [-h] [--checkonly] [--new] ARCTICONS_DIR

positional arguments:
  ARCTICONS_DIR  Path to the Arcticons directory

options:
  -h, --help     show this help message and exit
  --checkonly    Run checks only
  --new          Run a new Release

Instead of of having a category for every letter i merged them to A-Z. To have an Specific Letter you will still be able to scroll to it with the scrollbar #1938

[Donnnno]

Wow, that's so useful, thank you so much!

Could you add a description of the new prepare release script, with its options here?
https://github.com/Arcticons-Team/Arcticons/tree/main/other/scripts