Afs2-model

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- Add Requirement 16655 - [SDK] Fix decode data_dir message for apm source

- Add Requirement - [SDK] Can use blob credential in env without api version

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- Add Requirement 15395 - [SDK] Download model through boto3

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- Add Requirement - Support AFS 3.2 upload model to different blob.

- Remove model metadata API.

- Remove part of test case.

- Add Requirement - Update to get blob key credential.

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- Add Requirement 13878 - Support Coefficient parameter

- Fix Bug 13864 - Fix botocore upload incomplete model, and use boto3 instead.

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- Add Requirement 13390 - [SDK] Store dataset_id and target when upload model.

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- Add Requirement - [SDK] Update upload model default using blob mode.

- Add Requirement 12871 - [SDK] Add feature importance field.

- Remove EnSaaS 3.0 function and doc.