Closes#1346
`GetObject` and `HeadObject` return the `x-amz-tagging-count` header in the response, which specifies the number of tags associated with the object. This was already supported for `GetObject`, but missing for `HeadObject`. This implementation adds support for `HeadObject` in `azure` and `posix` and updates the integration tests to cover this functionality for `GetObject`.
Fixes#1385
When accessing a specific object version, the user must have the `s3:GetObjectVersion` permission in the bucket policy. The `s3:GetObject` permission alone is not sufficient for a regular user to query object versions using `HeadObject`.
This PR fixes the issue and adds integration tests for both `HeadObject` and `GetObject`. It also includes cleanup in the integration tests by refactoring the creation of user S3 clients, and moves some test user data to the package level to avoid repetition across tests.
