Migrate config to KV data format (#8392)

- adding oauth support to MinIO browser (#8400) by @kanagaraj
- supports multi-line get/set/del for all config fields
- add support for comments, allow toggle
- add extensive validation of config before saving
- support MinIO browser to support proper claims, using STS tokens
- env support for all config parameters, legacy envs are also
  supported with all documentation now pointing to latest ENVs
- preserve accessKey/secretKey from FS mode setups
- add history support implements three APIs
  - ClearHistory
  - RestoreHistory
  - ListHistory
- add help command support for each config parameters
- all the bug fixes after migration to KV, and other bug
  fixes encountered during testing.

cmd/lock-rest-server-common_test.go

@@ -41,7 +41,7 @@ func createLockTestServer(t *testing.T) (string, *lockRESTServer, string) {
 			lockMap:         make(map[string][]lockRequesterInfo),
 		},
 	}
-	creds := globalServerConfig.GetCredential()
+	creds := globalActiveCred
 	token, err := authenticateNode(creds.AccessKey, creds.SecretKey)
 	if err != nil {
 		t.Fatal(err)