Output mutant statuses filter

[rusinikita]

Proposed changes

I want to see only useful findings. But:

• Big projects leads to large number of printed mutants. A lot of them is KILLED
• Using --diff flag leads to SKIPPED is 90% of output

See docs change for flag design details.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc
• Lint and unit tests pass locally with my changes (make all)
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• Any dependent changes have been merged and published in downstream modules

Further comments

Closes #108 issue

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (ba6851a) 88.20% compared to head (91d49ce) 88.55%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #226      +/-   ##
==========================================
+ Coverage   88.20%   88.55%   +0.35%     
==========================================
  Files          21       22       +1     
  Lines        1433     1477      +44     
==========================================
+ Hits         1264     1308      +44     
  Misses        144      144              
  Partials       25       25              

Flag	Coverage Δ
unittests	88.55% <100.00%> (+0.35%)	⬆️

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.

[rusinikita]

Linter checks fails because of golangci-lint update. I fixed it in #228. Let's merge #228 first, then a will rebase this. Issues will be fixed

[giose86]

@rusinikita Hi! Just fix the check that is failing, the rest is fine :)