* list owned buckets
* simplify
* add unit tests
* no-owner buckets
* set identity id
* fallback to request header if iam is not enabled
* refactor to test
* fix comparing
* fix security vulnerability
* Update s3api_bucket_handlers.go
* Update s3api_bucket_handlers.go
* Update s3api_bucket_handlers.go
* set identity to request context
* remove SeaweedFSIsDirectoryKey
* remove obsolete
* simplify
* reuse
* refactor or remove obsolete logic on filer
* Removed the redundant check in GetOrHeadHandler
* surfacing invalid X-Amz-Tagging as a client error
* clean up
* constant
* reuse
* multiple header values
* code reuse
* err on duplicated tag key
