[Feature](sink) add copy mode to sink

[JNSimba]

Proposed changes

Currently sink.write-mode supports stream_load, and stream_load_batch is used for streamload import.
Now the import method of copy load is added to adapt to the scenario of Doris storage and calculation separation.
The import is divided into two steps:

1. First upload the data to object storage.
2. Then load the data on the object storage into Doris.

This import method is usually used for synchronization across vpc scenarios (flink cluster and doris cluster).

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/No)

Further comments

If this is a relatively large or complex change, kick off the discussion at [email protected] by explaining why you chose the solution you did and what alternatives you considered, etc...