Related to #31293#37031
This PR:
- Add DescribeReplica API
- Add unified RBAC v2 API names(AddPrivilegesToGroup,
RemovePrivilegesFromGroup, GrantPrivilegeV2, RevokePrivilegeV2)
- Mark old ones deprecated
Signed-off-by: Congqi Xia <congqi.xia@zilliz.com>