refactor(dask): use centralized function for Dask component names

[Alputer]

This PR refactors naming of Dask components which were previously hard-coded. Now, they are set centrally in a function that is placed in reana-commons.

Closes reanahub/reana#841

[tiborsimko]

todo: ‏We need to bump reana-commons for CI to pass after a new reana-commons alpha release.

[tiborsimko]

todo: ‏We need to bump reana-commons for CI to pass after a new reana-commons alpha release.

Also, in respect to changing the commit log message for r-commons (centralised -> central), we could adapt the release news item accordingly, to read:

refactor(dask): use central function for Dask K8s component names (#613)

[codecov]

Codecov Report

Attention: Patch coverage is 91.66667% with 1 line in your changes missing coverage. Please review.

Project coverage is 75.01%. Comparing base (2797300) to head (f252098).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
reana_workflow_controller/consumer.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #613      +/-   ##
==========================================
+ Coverage   74.98%   75.01%   +0.02%     
==========================================
  Files          17       17              
  Lines        1911     1913       +2     
==========================================
+ Hits         1433     1435       +2     
  Misses        478      478              

Files with missing lines	Coverage Δ
reana_workflow_controller/dask.py	76.36% <100.00%> (ø)
reana_workflow_controller/k8s.py	73.58% <100.00%> (+0.16%)	⬆️
reana_workflow_controller/opensearch.py	90.00% <100.00%> (+0.20%)	⬆️
reana_workflow_controller/rest/workflows.py	68.97% <100.00%> (ø)
reana_workflow_controller/workflow_run_manager.py	80.67% <100.00%> (ø)
reana_workflow_controller/consumer.py	53.89% <0.00%> (ø)