[Feature] Support DDL/DML on external catalog

[morningman]

Search before asking

• I had searched in the issues and found no similar issues.

Description

Before 2.0, Doris can only support query data from external catalog such as Hive, Hudi, etc.
Now we would like to support DDL/DML feature on external catalog

Use case

No response

Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[liugddx]

i want try

[lexluo09]

I'd like to try

[morningman]

We are working on the framework of this feature.
After the framework is stable, we'd like to invite more contributor to participate in developement.