[SysApps] Implement the Device Capabilities getDisplayInfo()

This provider is missing an Observer interface for notifications
of displays being connected and disconnected. This is very likely to
be platform dependent and we might need to add platform files.

Currently we only using a static method, but I'm keeping the GetInstance()
for the display monitoring implementation.
[SysApps] Compile Chromium's StorageMonitor as a module

The StorageMonitor is almost self-contained, despite adding itself
to the Chromium's Browser Process. We should work upstream to fix that.

Meanwhile we can compile it as module (and protect the Chromium specific bits
with a flag) so we can use it as backend for the Device Capabilities
getStorageInfo() for Linux, Mac and Windows.
[SysApps] Add a data provider for Linux based on Chromium's StorageMonitor

This provider has a big chance of being generic enough to be used for Mac and
Windows. The backend for Android was not implemented yet which makes me sad.

We will have to implement a custom provider for Android (upstream maybe?).
[SysApps] Add a simple test for Device Capabilities

Not to self: make a browsertest out of this. :)