Copy Text Link per Zatsune Sakurako

Copy the text of links without having to select it. Display a notification in case of copy error.

This addon is Free and Open-Source Software (FOSS), the source code is available here : https://github.com/ZatsuneSakurako/copy_text_link

This only modification on the code before publishing is a code cleaning on the debug (debug, console.*) except one in case of error reporting needed. The text of the link comes from https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/menus/OnClickData#linktext so if the link has no text, the URL will be copied instead. The text link is send to clipboard but is not stored or collected (no tracking in the code).

The addon logo has been made with these 2 following sources, both in Public Domain License:
- Pixabay 27848
- Pixabay 1271843

Russian translation (starting with version 2.1.0) by daimoniuma