UI inconsistencies in the EM when trying to install an extension that has its dependencies already installed

Steps to reproduce:

1. Search for the Wiki Manager API
2. Open the Dependencies tab. You will see that Old Core is Provided and that Application Manager API is not installed
3. Install the Application Manager API
4. Come back to the Wiki Manager API and make sure you reload/refresh the page so that it now displays the Application Manager API extension as Installed (in the Dependencies tab).
5. Press the Install button for the Wiki Manager API extension. The button will be greyed out and there will be no Progress tab.

Workaround: At step 4, make sure you don`t refresh the page and directly press the Install button after you`ve installed the Application Manager API in a different tab.