Refactor InternalUsers REST API test

[willyborankin]

Description

Split up UserApiTest into 3 diff tests:

• InternalUsersRestApiIntegrationTest
• InternalUsersRegExpPasswordRulesRestApiIntegrationTest

• InternalUsersScoreBasedPasswordRulesRestApiIntegrationTest

  Fixes:

• Added validation for the security roles for PATCH
• Added validation for restricted character in username for PATCH
• Final fix for #4166

Check List

• [x] New functionality includes testing
• [ ] New functionality has been documented
• [ ] New Roles/Permissions have a corresponding security dashboards plugin PR
• [ ] Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license. For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 65.21739% with 8 lines in your changes missing coverage. Please review.

Project coverage is 64.94%. Comparing base (6dedfb4) to head (7beb272).

Additional details and impacted files

[](https://app.codecov.io/gh/opensearch-project/security/pull/4481?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=opensearch-project) ```diff @@ Coverage Diff @@ ## main #4481 +/- ## ========================================== - Coverage 65.21% 64.94% -0.28% ========================================== Files 313 313 Lines 22047 22061 +14 Branches 3559 3560 +1 ========================================== - Hits 14378 14327 -51 - Misses 5895 5952 +57 - Partials 1774 1782 +8 ``` | [Files](https://app.codecov.io/gh/opensearch-project/security/pull/4481?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=opensearch-project) | Coverage Δ | | |---|---|---| | [...java/org/opensearch/security/user/UserService.java](https://app.codecov.io/gh/opensearch-project/security/pull/4481?src=pr&el=tree&filepath=src%2Fmain%2Fjava%2Forg%2Fopensearch%2Fsecurity%2Fuser%2FUserService.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=opensearch-project#diff-c3JjL21haW4vamF2YS9vcmcvb3BlbnNlYXJjaC9zZWN1cml0eS91c2VyL1VzZXJTZXJ2aWNlLmphdmE=) | `44.52% <75.00%> (-12.52%)` | :arrow_down: | | [...security/dlic/rest/api/InternalUsersApiAction.java](https://app.codecov.io/gh/opensearch-project/security/pull/4481?src=pr&el=tree&filepath=src%2Fmain%2Fjava%2Forg%2Fopensearch%2Fsecurity%2Fdlic%2Frest%2Fapi%2FInternalUsersApiAction.java&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=opensearch-project#diff-c3JjL21haW4vamF2YS9vcmcvb3BlbnNlYXJjaC9zZWN1cml0eS9kbGljL3Jlc3QvYXBpL0ludGVybmFsVXNlcnNBcGlBY3Rpb24uamF2YQ==) | `73.80% <60.00%> (-7.77%)` | :arrow_down: | ... and [7 files with indirect coverage changes](https://app.codecov.io/gh/opensearch-project/security/pull/4481/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=opensearch-project)