A feature-gate to limit CloneSet pod name within 63 chars or less

[veophi]

Ⅰ. Describe what this PR does

follow the name generation of Deployment https://github.com/kubernetes/kubernetes/blob/master/staging/src/k8s.io/apiserver/pkg/storage/names/generate.go#L53.

Ⅱ. Does this pull request fix one issue?

#1736

Ⅲ. Describe how to verify it

Ⅳ. Special notes for reviews

[codecov]

Codecov Report

Attention: Patch coverage is 85.71429% with 1 line in your changes missing coverage. Please review.

Project coverage is 49.18%. Comparing base (0d0031a) to head (e9aeb7e).
Report is 84 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/controller/cloneset/core/cloneset_core.go	85.71%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1737      +/-   ##
==========================================
+ Coverage   47.91%   49.18%   +1.26%     
==========================================
  Files         162      191      +29     
  Lines       23491    19576    -3915     
==========================================
- Hits        11256     9628    -1628     
+ Misses      11014     8695    -2319     
- Partials     1221     1253      +32     

Flag	Coverage Δ
unittests	49.18% <85.71%> (+1.26%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.