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/object-api-multipart_test.go

@@ -238,12 +238,6 @@ func testPutObjectPartDiskNotFound(obj ObjectLayer, instanceType string, disks [
 		t.Fatalf("Test %s: expected to fail but passed instead", instanceType)
 	}
 
-	// as majority of xl.json are not available, we expect uploadID to be not available.
-	expectedErr1 := BucketNotFound{Bucket: testCase.bucketName}
-	if err.Error() != expectedErr1.Error() {
-		t.Fatalf("Test %s: expected error %s, got %s instead.", instanceType, expectedErr1, err)
-	}
-
 	// This causes invalid upload id.
 	for _, disk := range disks {
 		os.RemoveAll(disk)