New developer command to test all third-party extensions

* `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

extensions.json

@@ -221,6 +221,17 @@
             "method": "git",
             "directory": "xExtension-Invidious"
         },
+        {
+            "name": "Invidious Video Feed",
+            "author": "Paul Tunbridge (forked from Korbak and Kevin Papst)",
+            "description": "Embed YouTube feeds inside article content, but with Invidious.",
+            "version": "1.1",
+            "entrypoint": "Invidious",
+            "type": "user",
+            "url": "https://github.com/tunbridgep/freshrss-invidious",
+            "method": "git",
+            "directory": "xExtension-Invidious"
+        },
         {
             "name": "Kagi Summarizer",
             "author": "Rudis Muiznieks",