[Feature] Support alter database to update comment and custom properties

[LiebingYu]

Search before asking

• I searched in the issues and found nothing similar.

Motivation

Support alter database to update comment and custom properties.

Solution

• Server side: Add alterDatabase for AdminGateway, and implement in CoordinatorService.
• Client side: Add alterDatabase for Admin, and implement in FlussAdmin.
• Flink side: Implement alterDatabase in FlinkCatalog.

Anything else?

No response

Willingness to contribute

• I'm willing to submit a PR!