Private Regions Tab

If server owner has
```
timings:
private-regions: true
regions-password: XXXXXXX
```
in their paper config, ensure regions tab does not get sent to the client unless they enter a password

A secondary local supplied password should also allow viewing the regions tab so that Paper trusted dev team can view it to assist without asking the server owner for a password.
If a region password is not supplied, generate one and print it in the upload response.