feat(Storage): Adding StorageBucket

[ruisebas]

Description

This PR adds the new StorageBucket protocol and its default implementations.
It also adds an optional bucket: StorageBucket parameter to the existing Request.Options enums.

General Checklist

• 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
• PR title conforms to conventional commit style
• New or updated tests include Given When Then inline code documentation and are named accordingly testThing_condition_expectation()
• If breaking change, documentation/changelog update with migration instructions

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

[github-actions]

API Breakage Report

💔 Public API Breaking Change detected:

Module: Amplify
Constructor StorageDownloadDataRequest.Options.init(accessLevel:targetIdentityId:pluginOptions:) has been removed
Constructor StorageDownloadDataRequest.Options.init(pluginOptions:) has been removed
Constructor StorageDownloadFileRequest.Options.init(accessLevel:targetIdentityId:pluginOptions:) has been removed
Constructor StorageDownloadFileRequest.Options.init(pluginOptions:) has been removed
Constructor StorageGetURLRequest.Options.init(accessLevel:targetIdentityId:expires:pluginOptions:) has been removed
Constructor StorageGetURLRequest.Options.init(expires:pluginOptions:) has been removed
Constructor StorageListRequest.Options.init(accessLevel:targetIdentityId:path:subpathStrategy:pageSize:nextToken:pluginOptions:) has been removed
Constructor StorageRemoveRequest.Options.init(accessLevel:pluginOptions:) has been removed
Constructor StorageUploadDataRequest.Options.init(accessLevel:targetIdentityId:metadata:contentType:pluginOptions:) has been removed
Constructor StorageUploadDataRequest.Options.init(metadata:contentType:pluginOptions:) has been removed
Constructor StorageUploadFileRequest.Options.init(accessLevel:targetIdentityId:metadata:contentType:pluginOptions:) has been removed
Constructor StorageUploadFileRequest.Options.init(metadata:contentType:pluginOptions:) has been removed