feat: add new constructor to support Redis username

[alordtas]

We need to provide the redis username when instantiating the adapter.
I added a new constructor which takes the username as an additional parameter, no change to the existing behaviour

[casbin-bot]

@tangyang9464 @imp2002 please review

[CLAassistant]

All committers have signed the CLA.

[codecov]

Codecov Report

Attention: Patch coverage is 11.11111% with 8 lines in your changes are missing coverage. Please review.

Project coverage is 60.92%. Comparing base (b487cc0) to head (353daba).
Report is 1 commits behind head on master.

Files	Patch %	Lines
src/main/java/org/casbin/adapter/RedisAdapter.java	11.11%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #18      +/-   ##
==========================================
- Coverage   63.01%   60.92%   -2.09%     
==========================================
  Files           3        3              
  Lines         146      151       +5     
  Branches       30       31       +1     
==========================================
  Hits           92       92              
- Misses         36       41       +5     
  Partials       18       18              

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[hsluoyz]

@alordtas can you also update the README about this usage?

[github-actions]

🎉 This PR is included in version 1.5.0 🎉

The release is available on:

• GitHub release
• v1.5.0

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