Support multitasking in iPad (aka split view)

This issue needs to be tested in an iPad. Install the app in an iPad device. In the iPad list of apps, tap and hold the Moodle app's icon until you can drag it, and then drag it into the docker (the bottom bar, that it usually haves the mail app, Safari, etc.). Open the Safari app. With the Safari app open, slide your finger from the bottom of the screen to the top, so the docker appears (but the Safari app shouldn't be minimized). Tap and hold the Moodle app's icon until you can drag it, and then drag it over the Safari app. Check that the app is placed in a "small" window over the Safari app. Try with the different orientations and check how the app behaves, for example, if split view is displayed or not when browsing course participants, text editor works, videos play, etc...