[ews] Status bubble should show previous failures if any in case patch is skipped. For e.g.: if a patch failed EWS, and someone lands/obsoletes the patch, and then click on 'Retry failed builds' button, status-bubble for would be white (skipped). However the status-bubble doesn't indicate that before being skipped, patch did encountered failures. We should update the status-bubbble tool-tip for skipped patches so as to indicate the previous failures.
Created attachment 381576 [details] Patch
Sample run: Skipped build with previous failed build: https://ews.webkit-uat.org/status-bubble/381492/ (look at 'style' bubble) Skipped build without previous failed build: https://ews.webkit-uat.org/status-bubble/381322/
Committed r251453: <https://trac.webkit.org/changeset/251453>
<rdar://problem/56514010>