[che-dev] <username>-che as default namespace for Che workspaces

[Oleksandr Andriienko <oandriie@xxxxxxxxxx>]

Hello. We finally merged pull request https://github.com/eclipse/che-operator/pull/166 to enable  "<username>-che" as default namespace for Eclipse Che installed via che-operator (issue https://github.com/eclipse/che/issues/15493). Thanks a lot to the platform team for initial work on this pull request. Deploy team analyzed and completed contribution: we applied permission finalizers, improved permissions set, implemented permission clean up when workspace namespace default configuration changed, applied unit test, made permissions set working for few parallel working Che installations,  applied workspace namespace default fallback when Che installation doesn't have enough permissions for  <username>-che as default namespace.
After merging this pull request Eclipse Che executes workspace in the namespace  "<username>-che" by default for Openshift(when Openshift oAuth enabled and disabled) and k8s platforms.