Addon UUID replacer for themes modifying about:addons

**Description**
A UUID value is required to access and modify the extension's page CSS.
UUID can be identified through `about:debugging#/runtime/this-firefox` or `pref.js`(`extensions.webextensions.uuid`).

**Example**
Here is an example of running a replacement.
- Shadow Fox
- Replacer: https://github.com/overdodactyl/ShadowFox/blob/master/scripts/uuids.sh
- Apply: https://github.com/overdodactyl/ShadowFox/tree/master/css/userContent-files/webextension-tweaks
- Quantum Nox Firefox Dark Full Theme
- Replacer: https://github.com/Izheil/Quantum-Nox-Firefox-Dark-Full-Theme/tree/master/Installers/Addons%20UUID%20replacer
- Apply: https://github.com/Izheil/Quantum-Nox-Firefox-Dark-Full-Theme/blob/master/Full%20dark%20theme/addons.css

**More Context**
IMO, extension ID can to be the target.