Sticker-convert

- Add display version in CLI and GUI
- Fix importing module (https://github.com/laggykiller/sticker-convert/issues/46)

- Fix run_me_first.command with space in path
- Change domain detection
- Update screenshots
- Update README

Rework of compression scripts; Create pip package

- Eliminate use of external binaries
- ImageMagick
- ffmpeg
- apngasm
- apngdis
- optipng
- pngquant
- pngnq-s9
- zip
- Write into bytesio instead of disk whenever possible
- Using apngasm-python to create APNG
- Huge improvement in compression speed, esp. APNG (About x4 speed)
- Remove telegram_vector compression option
- Create pip package
- Fix some compression options listed as input options in CLI
- Restructure project directory structure
- Clean importing
- Update documentation

- Add field highlighting in GUI
- Code restructure & cleanup esp. in downloader and exporter scripts
- Fix incorrect compression preset for telegram
- Fix README incorrect info about Signal & Telegram credential requirements

- Fix check for author.txt
- Fix unicode author.txt and title.txt causing crash
- Prioritize English title name for Line sticker
- Update documentation