Closes#1595
This implementation diverges from AWS S3 behavior. The `CreateBucket` request body is no longer ignored. Based on the S3 request body schema, the gateway parses only the `LocationConstraint` and `Tags` fields. If the `LocationConstraint` does not match the gateway’s region, it returns an `InvalidLocationConstraint` error.
In AWS S3, tagging during bucket creation is supported only for directory buckets. The gateway extends this support to general-purpose buckets.
If the request body is malformed, the gateway returns a `MalformedXML` error.