lock: improve locker initialization at init (#8776)

Use reference format to initialize lockers
during startup, also handle `nil` for NetLocker
in dsync and remove *errorLocker* implementation

Add further tuning parameters such as

 - DialTimeout is now 15 seconds from 30 seconds
 - KeepAliveTimeout is not 20 seconds, 5 seconds
   more than default 15 seconds
 - ResponseHeaderTimeout to 10 seconds
 - ExpectContinueTimeout is reduced to 3 seconds
 - DualStack is enabled by default remove setting
   it to `true`
 - Reduce IdleConnTimeout to 30 seconds from
   1 minute to avoid idleConn build up

Fixes #8773

cmd/background-heal-ops.go

@@ -61,6 +61,7 @@ func (h *healRoutine) run() {
 			if !ok {
 				break
 			}
+
 			if httpServer := newHTTPServerFn(); httpServer != nil {
 				// Wait at max 10 minute for an inprogress request before proceeding to heal
 				waitCount := 600