feat: Implements object meta properties for CopyObject in azure and posix backends.

Fixes #998
Closes #1125
Closes #1126
Closes #1127

Implements objects meta properties(Content-Disposition, Content-Language, Content-Encoding, Cache-Control, Expires) and tagging besed on the directives(metadata, tagging) in CopyObject in posix and azure backends. The properties/tagging should be coppied from the source object if "COPY" directive is provided and it should be replaced otherwise.

Changes the object copy principle in azure: instead of using the `CopyFromURL` method from azure sdk, it first loads the object then creates one, to be able to compare and store the meta properties.

s3err/s3err.go

@@ -144,6 +144,7 @@ const (
 	ErrUnexpectedContent
 	ErrMissingSecurityHeader
 	ErrInvalidMetadataDirective
+	ErrInvalidTaggingDirective
 	ErrKeyTooLong
 	ErrInvalidVersionId
 	ErrNoSuchVersion
@@ -597,6 +598,11 @@ var errorCodeResponse = map[ErrorCode]APIError{
 		Description:    "Unknown metadata directive.",
 		HTTPStatusCode: http.StatusBadRequest,
 	},
+	ErrInvalidTaggingDirective: {
+		Code:           "InvalidArgument",
+		Description:    "Unknown tagging directive.",
+		HTTPStatusCode: http.StatusBadRequest,
+	},
 	ErrInvalidVersionId: {
 		Code:           "InvalidArgument",
 		Description:    "Invalid version id specified",