Make all Office UI Fabric Icons available as Icons

[TiagoFreire]

Microsoft already has a vast set of standard icons for the web, in Microsoft UI fabric icons.

https://uifabricicons.azurewebsites.net/

It would be very useful if we can use Fabric icons in the PowerApps Icons control. 

Would reduce the necessity of importing a lot of graphics for UI.

[CNT]

A Must.