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.

docs/debugging/README.md

@@ -0,0 +1,25 @@
+# MinIO Server Debugging Guide [![Slack](https://slack.min.io/slack?type=svg)](https://slack.min.io) [![Docker Pulls](https://img.shields.io/docker/pulls/minio/minio.svg?maxAge=604800)](https://hub.docker.com/r/minio/minio/)
+
+### HTTP Trace
+HTTP tracing can be enabled by using [`mc admin trace`](https://github.com/minio/mc/blob/master/docs/minio-admin-complete-guide.md#command-trace---display-minio-server-http-trace) command.
+
+Example:
+```sh
+minio server /data
+```
+
+Default trace is succinct only to indicate the API operations being called and the HTTP response status.
+```sh
+mc admin trace myminio
+```
+
+To trace entire HTTP request
+```sh
+mc admin trace --verbose myminio
+```
+
+To trace entire HTTP request and also internode communication
+```sh
+mc admin trace --all --verbose myminio
+```
+