[feature](light-schema-change) add a http interface for flink-doris-connector

[Lchangliang]

Proposed changes

Issue Number: close #xxx

Problem summary

The http interface is use for flink-doris-connector to sync ddl command from mysql to doris. flink-doris-connector need to check the downstream table whether enable light schema change. If true, connector can sync the add/drop column command to doris.

Checklist(Required)

1. Does it affect the original behavior:
   • Yes
   • No
   • I don't know
2. Has unit tests been added:
   • Yes
   • No
   • No Need
3. Has document been added or modified:
   • Yes
   • No
   • No Need
4. Does it need to update dependencies:
   • Yes
   • No
5. Are there any changes that cannot be rolled back:
   • Yes (If Yes, please explain WHY)
   • No

Further comments

If this is a relatively large or complex change, kick off the discussion at dev@doris.apache.org by explaining why you chose the solution you did and what alternatives you considered, etc...