Thunderbird 128 ESR

[HorlogeSkynet]

Description

• [x] Upstream mailnews.js comparison (https://searchfox.org/comm-esr115/source/mailnews/mailnews.js & https://searchfox.org/comm-esr128/source/mailnews/mailnews.js)
• [x] Arkenfox v115.1 -> v126.1 migration (https://github.com/arkenfox/user.js/compare/115.1...126.1#diff-417e8f625f16252f8ace3b0791d24c9b073d7394e9216c7b5d14a516d2572277)
• [x] Arkenfox v126.1 -> v128 migration for new ESR (:warning: waiting for arkenfox/user.js#1872 & arkenfox/user.js#1862)
• [x] Include tooling scripts from Arkenfox upstream (see #41 and all the other issues)

How has this been tested ?

Untested.

Types of changes :

• [x] Bug fix (non-breaking change which fixes an issue)
• [X] Typo / style fix (non-breaking change which improves readability)
• [X] New feature (non-breaking change which adds functionality)
• [X] Breaking change (fix or feature that would cause existing functionality to change)

Checklist :

• [X] My changes looks good ;
• [X] I agree that my code may be modified in the future ;
• [X] My code follows the code style of this project (see .eslint.config.mjs).

[atomGit]

i didn't go through all this - if it works for you, i'm fine with it :)