RBAC: LDAP: Support "user" subject

[sm-shevchenko]

Issue submitter TODO list

• I've searched for an already existing issues here
• I'm running a supported version of the application which is listed here and the feature is not present there

Is your proposal related to a problem?

Sometimes the same LDAP/AD security group can be used to restrict access in a different applications, but there is a need to add 1-2 accounts of this group to access to only one additional application (KafkaUI for example).
It would be nice to be able to flexibly configure in this case with a role in KafkaUI instead of creating a new additional access group that would be >90% duplicate of existing group.

Describe the feature you're interested in

'user' objects are available as subject for the RBAC with LDAP/AD

Describe alternatives you've considered

No response

Version you're running

0.7.0

Additional context

No response

[engineater]

I would like to add some text for this issue.
For me is important that if I in settings ldap choose

  user-filter-search-filter: "(&(sAMAccountName={0})(objectclass=user))"

I could choose, a values of sAMAccountName in RBAC settings

       - provider: ldap
         type: user
         value: 
             # sAMAccountName values
             - user1
             - user2
             - user3