Improve Che Release process cico_release.sh script

[nickboldt]

Some enhancements we can do for the Che release in 7.13 (verify in 7.14):

• ensure hub installed so PRs can be generated (right now we just get a branch and have to manually create the PR and wait for it to be approved/merged)

• install jq correctly from epel7 - https://medium.com/@gchandra/install-jq-on-centos-7-459dd650baa3

• switch to Maven 3.5 - https://centos.pkgs.org/7/centos-sclo-rh-x86_64/rh-maven35-maven-3.5.0-4.2.el7.noarch.rpm.html

• generate PRs for registries & verify they can be approved and merged (ECA check passes)

  • Verify with 7.13.1 - new plugins only [release] Add 7.13.1 plugins in master che-plugin-registry#467

• generate PRs for che parent, dashboard, ws-loader, server & verify they can be approved and merged (ECA check passes)

  • verify with 7.14.0 - updates to VERSION files and new plugins
  • ensure latest.txt file is also updated when pushing new theia/machine exec plugins to registry

• change order of steps (devfile, theia, machineexec, plugin reg) so we can run first 3 in parallel, then wait until done before triggering plugin registry

• switch to using dashboard and workspace loader artifacts as containers instead of maven artifacts

  • repeat this change for CRW - Use 7.13.0 Dashboard and workspace-loader as docker containers redhat-developer/devspaces#289
  • Hosted Che

Followup items in #17101

[nickboldt]

From Mykhailo:

finished the release of 7.13 che-server and everything, here are the PRs generated by the bot
(duplicated text in PR body will be fixed next time)
eclipse-che/che-parent#174
#16931

I decided to move away from modules/submodules, since I don't need them much anymore, so by the night I was trying to finally get it built in one go.

Was thinking there is more to it, than it turned out to be, so ended up with a simple structure, where all projects have their release version set, then build dashboard & ws-loader in parallel, then build and deploy che-parent & che individually, and then the rest of the images, and then bump the versions

And today had several reruns because of missing perms for CI bot to push into new quay repos, attempting to build centos image, and some other bash errors.

Now, if nothing changes, the script should go through much of a change like that anymore, even if we would not release che-parent next time

registry hub PRs were not generated; had to be done by hand this time (again).