Improve development flow with skaffold

[akurinnoy]

What does this PR do?

This PR improves the development flow on the dogfooding cluster when it's needed to continuously update the dashboard on a remote cluster to review or test any changes. Skaffold is able to automate all steps needed, like building a new image, pushing the image to the repo, and then updating the CR.

https://youtu.be/MeXLKcX-mmU

What issues does this PR fix or reference?

resolves eclipse-che/che#22116

Is it tested? How?

1. Create a new workspace using this link: https://che-dogfooding.apps.che-dev.x6e0.p1.openshiftapps.com/#https://github.com/eclipse-che/che-dashboard/tree/skaffold
2. Log in to the remote cluster with Eclipse Che deployed.
3. Log in to the container registry you want to use.

4.  export DEFAULT_REPO=<your-registry>/<project-id>

5. Do some changes in the che-dashboard project, and run yarn build.
6. Run

   scaffold run --cleanup=false --default-repo=$DEFAULT_REPO

   Skaffold builds a new image, pushes it to the registry, and patches the CR.
7. Watch changes you've made in the dashboard on the remote cluster.

[che-bot]

Click here to review and test in web IDE:

[github-actions]

Docker image build succeeded: quay.io/eclipse/che-dashboard:pr-869

[github-actions]

Docker image build succeeded: quay.io/eclipse/che-dashboard:pr-869

[github-actions]

Docker image build succeeded: quay.io/eclipse/che-dashboard:pr-869

[openshift-ci]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: akurinnoy, ibuziuk, olexii4

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[ibuziuk]

/retest

[codecov]

Codecov Report

Merging #869 (7b1dfb1) into main (58cdd35) will decrease coverage by 0.01%.
Report is 9 commits behind head on main.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #869      +/-   ##
==========================================
- Coverage   81.59%   81.58%   -0.01%     
==========================================
  Files         347      347              
  Lines       35874    35881       +7     
  Branches     2230     2231       +1     
==========================================
+ Hits        29271    29275       +4     
- Misses       6581     6584       +3     
  Partials       22       22              

Flag	Coverage Δ
unittests	81.58% <ø> (-0.01%)	⬇️

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see 2 files with indirect coverage changes