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.

browser/webpack.config.js

@@ -74,7 +74,8 @@ var exports = {
     proxy: {
       '/minio/webrpc': {
 	target: 'http://localhost:9000',
-	secure: false
+  secure: false,
+  headers: {'Host': "localhost:9000"}
       },
       '/minio/upload/*': {
 	target: 'http://localhost:9000',