feat: merge experimental-licenses-summary and experimental-licenses into one generic flag

[hogo6002]

Partially resolves #1644

This PR merges experimental-licenses-summary and experimental-licenses into one generic flag:
--experimental-licenses: only shows the summary
--experimental-licenses=[allowlist]: shows both the summary and the packages with violations

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 85.12397% with 18 lines in your changes missing coverage. Please review.

Project coverage is 64.61%. Comparing base (91f56a9) to head (e2ecb13).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/osvscanner/osvscanner.go	78.57%	6 Missing and 3 partials ⚠️
cmd/osv-scanner/internal/helper/helper.go	81.81%	4 Missing and 2 partials ⚠️
internal/output/table.go	90.90%	1 Missing and 1 partial ⚠️
pkg/reporter/vertical_reporter.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1651      +/-   ##
==========================================
+ Coverage   64.56%   64.61%   +0.04%     
==========================================
  Files         155      155              
  Lines       15997    16003       +6     
==========================================
+ Hits        10329    10340      +11     
+ Misses       4984     4980       -4     
+ Partials      684      683       -1     

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[another-rex]

Can you add an example of just license summary with no vulnerabilities? (With the table output)