[CRW][z&p] 3.0 :: switch from openj9 to openjdk udi sidecar; update EAP XP 3 in devfile reg

Due to licensing issues, Red Hat can no longer ship openj9 binaries.  z & p architectures had used openj9 due to performance considerations, but will now switch to openjdk (inline with x).

Changes to be done for 3.0:

• openj9 images will be deprecated and point back to the jdk images in Comet - RCMAUTO-5388 DONE
• x64 images will be switched to multiarch x/z/p - PR 186 DONE
• images that could install something that doesn't exist for z/p (eg. dotnet rpms) will need to do an arch check before installing and skip that step if arch != x64 DONE
  • images that do tests for binaries that might not exist (see `tests/basic_test.yaml` in affected folders in codeready-workspaces-images repo) need to also be arch-aware and not try to test dotnet on an arch for which it can't be installed -> PR 186 DONE
• operator, devfile and plugin registries will need to be updated to NOT switch to plugin-*-openj9 images in place of plugin-* images - c85f4b DONE
• jobs need to be updated to not build udi-openj9:
  • job-config update: 0eb440 DONE
  • job updates: MR 1082
• Doc updates to crw-images repo - mark udi-openj9 folder deprecated; remove mention of udi-openj9 from the udi folder: 2ce13d DONE

• operator, devfile and plugin registries will need to continue to switch to sso / eap images until such time as THOSE projects rebuild their images to be multiarch x/z/p with openjdk; then we need to rebuild the registries/operator AGAIN to switch over to the new 3-arch openjdk images: DONE

• deprecate old images in Comet; update java image descriptions (both jdk and j9) to mention Knowledge Base article (see RHMWRT-666): DONE

See also CRW-2750 for updates to CRW 2.15.1, and possible followup work in CRW-2760 for 3.x.