feat(storage): Remove the async throws from the apis that return task

[royjit]

Issue #, if available: #2546

Description of changes:
Update the storage api to remove the async throws from apis that return task.

Check points: (check or cross out if not relevant)

• Added new tests to cover change, if needed
• Build succeeds with all target using Swift Package Manager
• All unit tests pass
• All integration tests pass
• Security oriented best practices and standards are followed (e.g. using input sanitization, principle of least privilege, etc)
• Documentation update for the change if required Update storage api doc to reflect api changes docs#4799
• PR title conforms to conventional commit style
• If breaking change, documentation/changelog update with migration instructions

DataStore checkpoints (check when completed)

• Ran AWSDataStorePluginIntegrationTests
• Ran AWSDataStorePluginV2Tests
• Ran AWSDataStorePluginMultiAuthTests
• Ran AWSDataStorePluginCPKTests
• Ran AWSDataStorePluginAuthCognitoTests
• Ran AWSDataStorePluginAuthIAMTests

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[ruisebas]

Would this be a good time to add a default = nil to options as well?

Same for the AWSS3StoragePlugin+AsyncClientBehavior.swift file

[royjit]

Changed