Support updating optional installed apps via git (#6513)

* WIP: Support updating optional installed apps via git

* support app source update via cli

* Update app_languages.php

* Update index.php

* Refactor App Git updating

Refactor Optional App Git updating for more resilience and better handling of ssh remotes and to only update each repository once.

* git app updates fix gui updates for repo based updating

core/upgrade/upgrade.php

@@ -286,4 +286,22 @@
 			}
 	}
 
-?>
+//upgrade optional apps
+	if ($upgrade_type == 'apps') {
+
+		$app_list = git_find_repos($_SERVER["PROJECT_ROOT"]."/app");
+
+		if (!is_array($app_list)) {
+			exit;
+		}
+		print_r($app_list);exit;
+		foreach ($app_list as $repo => $apps) {
+			$path = $repo;
+			$git_result = git_pull($path);
+			foreach ($git_result['message'] as $response_line) {
+				echo $repo . ": " . $response_line . "\n";
+			}
+		}
+	}
+
+?>