[Backport 2.x] Add support for PBKDF2 for password hashing & add support for configuring BCrypt and PBKDF2

[opensearch-trigger-bot]

Backport 8d29b11 from #4524.

[codecov]

Codecov Report

Attention: Patch coverage is 89.50000% with 21 lines in your changes missing coverage. Please review.

Project coverage is 65.42%. Comparing base (ed67676) to head (96bab83).

Additional details and impacted files

@@            Coverage Diff             @@
##              2.x    #4551      +/-   ##
==========================================
+ Coverage   65.13%   65.42%   +0.29%     
==========================================
  Files         313      316       +3     
  Lines       21943    22105     +162     
  Branches     3556     3572      +16     
==========================================
+ Hits        14292    14462     +170     
+ Misses       5866     5852      -14     
- Partials     1785     1791       +6     

Files	Coverage Δ
.../opensearch/security/OpenSearchSecurityPlugin.java	84.63% <100.00%> (+0.26%)	⬆️
...pensearch/security/auditlog/impl/AuditMessage.java	76.38% <100.00%> (ø)
...ensearch/security/hasher/BCryptPasswordHasher.java	90.47% <100.00%> (+4.76%)	⬆️
...g/opensearch/security/support/ConfigConstants.java	95.23% <100.00%> (+0.23%)	⬆️
...y/tools/democonfig/SecuritySettingsConfigurer.java	76.71% <100.00%> (ø)
...search/security/hasher/AbstractPasswordHasher.java	91.66% <91.66%> (ø)
...nsearch/security/hasher/PasswordHasherFactory.java	90.90% <90.90%> (ø)
...ensearch/security/hasher/PBKDF2PasswordHasher.java	78.57% <78.57%> (ø)
...ain/java/org/opensearch/security/tools/Hasher.java	81.89% <89.00%> (+75.83%)	⬆️

... and 4 files with indirect coverage changes