log: Store http request/responses in a log file (#4804)

When MINIO_TRACE_DIR is provided, create a new log file and store all
HTTP requests + responses data, body are excluded to reduce memory
consumption. MINIO_HTTP_TRACE=1 enables logging. Use non mem
consuming http req/resp recorders, the maximum is about 32k per request.
This logs to STDOUT, body logging is disabled for PutObject PutObjectPart
GetObject.

cmd/lock-instrument_test.go

@@ -218,6 +218,7 @@ func TestNewDebugLockInfoPerVolumePath(t *testing.T) {
 
 // TestNsLockMapStatusBlockedToRunning - Validates the function for changing the lock state from blocked to running.
 func TestNsLockMapStatusBlockedToRunning(t *testing.T) {
+
 	testCases := []struct {
 		volume      string
 		path        string