[feat] Add targz transparent extract support (#11849)

This feature brings in support for auto extraction
of objects onto MinIO's namespace from an incoming
tar gzipped stream, the only expected metadata sent
by the client is to set `snowball-auto-extract`.

All the contents from the tar stream are saved as
folders and objects on the namespace.

fixes #8715

cmd/format_string.go

@@ -0,0 +1,28 @@
+// Code generated by "stringer -type=format -trimprefix=format untar.go"; DO NOT EDIT.
+
+package cmd
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[formatUnknown-0]
+	_ = x[formatGzip-1]
+	_ = x[formatZstd-2]
+	_ = x[formatLZ4-3]
+	_ = x[formatS2-4]
+	_ = x[formatBZ2-5]
+}
+
+const _format_name = "UnknownGzipZstdLZ4S2BZ2"
+
+var _format_index = [...]uint8{0, 7, 11, 15, 18, 20, 23}
+
+func (i format) String() string {
+	if i < 0 || i >= format(len(_format_index)-1) {
+		return "format(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _format_name[_format_index[i]:_format_index[i+1]]
+}