Feature/example app navigation

[wvanhaevre]

This is an initial setup for a more structured example application. The goal is to add more, feature-specific samples as we go along.

Currently we have:

• minimal setup: set source and start playing. No UI
• extended setup: the setup as we had it in the previous example app.
• presentationModes setup: a sample to demonstrate inline, pip and fullscreen presentationMode changes.
• drm setup: a sample to demonstrate drm connector usage
• sideloaded texttrack" a sample playing a source with a sideloaded texttrack
• 4 analytics connectors samples: conviva, comscore, nielsen and adobe