Bypass some steps in highlighted event propagation - prep.

Modify test utils methods
Add ui tree utils method
Rename viewer events:
- HighlightedChange -> HighlightedIdChange
- SelectedTreeChange -> HighlightedNodeChange
to better differentiate between propagating just the string id and propagating the entire node

Bug: 293579389
Test: npm run test:unit:ci
Change-Id: I2005e06d02902b71b993f2185607964b187a005c
14 files changed