GNOME Shell integration by Yuri Konotopov

Git tag: https://gitlab.gnome.org/GNOME/gnome-browser-extension/-/tags/v12

## Changes

- Rewritten extension to support [Manifest V3](https://developer.chrome.com/docs/extensions/develop/migrate/what-is-mv3)
- Added support for https://extensions-next.gnome.org
- Improved Firefox support

## Internal changes

- Dropped Opera compatibility code
- Dropped deprecated browser notifications code
- Dropped update check
- Moved release notes to GNOME Gitlab Pages
- Rewritten extensions in vanilla js and dropped all external libraries
- Formatted code to follow modern code style
- Fixed Python3 usage in build system (thanks to Keith Kyzivat, !50)
- Added devcontainer configuration

## Translations

- Athmane MOKRAOUI (kab)
- Fran Dieguez (gl)
- Hugo Carvalho (pt)
- Matej Urbančič (sl)
- Sabri Ünal (tr)
- Scrambled 777 (hi)
- Zurab Kargareteli (ka)