issue: #43897
- RBAC(Roles/Users/Privileges/Privilege Groups) is implemented by
WAL-based DDL framework now.
- Support following message type in wal `AlterUser`, `DropUser`,
`AlterRole`, `DropRole`, `AlterUserRole`, `DropUserRole`,
`AlterPrivilege`, `DropPrivilege`, `AlterPrivilegeGroup`,
`DropPrivilegeGroup`, `RestoreRBAC`.
- RBAC can be synced by new CDC now.
- Refactor some UT for RBAC.
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Signed-off-by: chyezh <chyezh@outlook.com>
