add banned-by label to BannedUser CRs

[MatousJobanek]

KUBESAW-123

add toolchain.dev.openshift.com/banned-by label (by reading the name from ksctl.yaml file) to BannedUser CRs created by ksctl ban command

[codecov]

Codecov Report

Attention: Patch coverage is 70.00000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 66.43%. Comparing base (88dface) to head (c0939f3).

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #41      +/-   ##
==========================================
+ Coverage   66.41%   66.43%   +0.01%     
==========================================
  Files          41       41              
  Lines        2269     2276       +7     
==========================================
+ Hits         1507     1512       +5     
- Misses        583      584       +1     
- Partials      179      180       +1     

Files	Coverage Δ
pkg/cmd/ban.go	71.79% <70.00%> (-0.04%)	⬇️