minor README edits for UI testing
add detailed matching for tree path finding
add keyword for checking thumbnail border color
add Insight UI test for selection synchronization
add tiny blank images to test repository
import new tiny images for UI testing
add Insight UI tests for thumbnail rendering
Merge pull request #1635 from mtbc/insight-ui-image-tests-11446

fix #11446: add robot framework scripts for testing the Insight data browser (rebased)