Add TreeView data model and hook up existing test data - #4304

Add TreeView data model and hook up existing test data#4304

Derek Keeler (d3r3kk) merged 8 commits into

microsoft:mastermicrosoft/vscode-python:masterfrom

d3r3kk:4273_test_explorer_datamodeld3r3kk/vscode-python:4273_test_explorer_datamodelCopy head branch name to clipboard