Add GH workflows for cherry-picking PRs to release branches

[pmacik]

Changes

This PR adds GH workflows to automate release-branch cherry-picking process. It goes as follows - as soon as the release-labeled PR to master is merged:

• A cherry-pick PR branch is created based on the release branch label of the original PR
• Original PR commit from master is cherry-picked and added on top of the cherry-pick PR branch
• A cherry-pick PR is sent from the cherry-pick PR branch to the release branch
• Normal PR checking flow is excercised including all the CI and approval
• Once the cherry-pick PR is merged the cherry-pick PR branch is deleted

Submitter Checklist

As the author of this PR, please check off the items in this checklist:

• Docs
  included if any changes are user facing
• Tests
  included if any functionality added or changed. For bugfixes please include tests that can catch regressions
• All acceptance test scenarios included in the PR which verifies a bugfix or a requested feature reported by a non-member are tagged with @external-feedback tag.
• Follows the commit message standard

[openshift-ci]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[codecov]

Codecov Report

Merging #1217 (1795e0c) into master (0535239) will not change coverage.
The diff coverage is n/a.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1217   +/-   ##
=======================================
  Coverage   58.06%   58.06%           
=======================================
  Files          33       33           
  Lines        2797     2797           
=======================================
  Hits         1624     1624           
  Misses       1018     1018           
  Partials      155      155           

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[baijum]

/lgtm

[dperaza4dustbit]

/lgtm
/approve

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dperaza4dustbit

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• OWNERS [dperaza4dustbit]

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