Various test fixes (#873)

* Switch back to macos-12 and see if the tests work

* Fix unit tests, add default invited, joined and active member counts to the mock room proxy

* Try running UI tests on 14.3 but on an existing iPad simulator

* Revert "Try running UI tests on 14.3 but on an existing iPad simulator"

This reverts commit b075e7fa384330a9070dc35ed4dded57e0af26e1.

ElementX/Sources/Application/AppCoordinator.swift

@@ -160,7 +160,7 @@ class AppCoordinator: AppCoordinatorProtocol {
             case (.signingOut, .completedSigningOut(let isSoft), .signedOut):
                 self.presentSplashScreen(isSoftLogout: isSoft)
             case (.signedIn, .clearCache, .initial):
-                clearCache()
+                self.clearCache()
             default:
                 fatalError("Unknown transition: \(context)")
             }