Provide hint in doc to use Update-AzMariaDBServer & Update-AzMariaDBServerConfiguration as a candidate for each other.

## Description of the new feature
Customers have difficult to choose between Update-AzMariaDBServer & Update-AzMariaDBServerConfiguration when they want to update setting of server.
## Proposed implementation details (optional)
Improve the docs of these two cmdlets in MariaDB to tell users to use the other cmdlet if the current one is not right for what they want to do.

Start by locating the documentation entries for Update-AzMariaDBServer and Update-AzMariaDBServerConfiguration and compare the settings each cmdlet supports. Add a clear cross-reference explaining when users should try the other cmdlet, then review both entries to confirm the guidance is visible and consistent.

Written by the indexing model from the issue text.