This commit overide style for tree items rendering, to fit with wireframes.
It adds a new Highlight shadow, new item separator, new Selected style.
Items can also have an array of "contextual views" that will be rendered only
on mouse hovers events.
It also introduce support for Ring official colors.

Issue: #79400, #79398
Change-Id: I8d227955f9afe25240b1ece991c57a3cbf996474