New developer command to test all third-party extensions

[Alkarex]

• composer run-script phpstan-third-party
• Rename the directory for generate.php to third-party instead of tmp
• Take advantage of PHPStan checkMissingOverrideMethodAttribute https://phpstan.org/config-reference#checkmissingoverridemethodattribute
• Detected and fixed bug in URL of https://github.com/tunbridgep/freshrss-invidious

[Alkarex]

Ping @aledeg @Frenzie if you have any comments

[Alkarex]

PR to third-party extension ( @nicofrand ) so that they all pass the test https://framagit.org/nicofrand/xextension-togglablemenu/-/merge_requests/1

[Alkarex]

Corresponding PR in core FreshRSS https://github.com/FreshRSS/FreshRSS/pull/6273