throw proper error when port is not accessible
for the regular user, this is possibly a regression.
```
ERROR Unable to start the server: Insufficient permissions to use specified port
> Please ensure MinIO binary has 'cap_net_bind_service=+ep' permissions
HINT:
Use 'sudo setcap cap_net_bind_service=+ep /path/to/minio' to provide sufficient permissions
```
minio server /data{1..4} shows an error about inability to bind a port, though
the real problem is /data{1..4} cannot be created because of the lack of
permissions.
This commit fix the behavior.
This change is related to larger config migration PR
change, this is a first stage change to move our
configs to `cmd/config/` - divided into its subsystems
* Cleanup ui-errors and print proper error messages
Change HELP to HINT instead, handle more error
cases when starting up MinIO. One such is related
to #8048
* Apply suggestions from code review