Update contribution context viewer to use a hierarchical grid.
Update contribution context viewer to use a hierarchical grid.

srdjan-bozovic/vso-extension-samples,Microsoft/vsts-extension-samples,Microsoft/vso-extension-samples,Microsoft/vsts-extension-samples,Microsoft/vsts-extension-samples,srdjan-bozovic/vso-extension-samples,srdjan-bozovic/vso-extension-samples,Microsoft/vso-extension-samples,Microsoft/vso-extension-samples