Issue 257: Server "Admins only" mode

[Veritania]

Summary

This is a step on the path to solve #257
This change hooks up two new admin commands for the in-game chat => #relayclose and #relayopen
They require accessLevel of admin

PerpetuumServer/src/Perpetuum/Commands.cs

Lines 1054 to 1064 in bd606e2

	public static readonly Command RelayOpen = new Command
	{
	Text = "relayOpen",
	AccessLevel = AccessLevel.admin
	};
	public static readonly Command RelayClose = new Command
	{
	Text = "relayClose",
	AccessLevel = AccessLevel.admin
	};

By default the server is starting in "relayopen" mode, meaning it is open to the public and anyone can join. (This is unchanged behaviour)

Once an admin has #secured a channel and then ran the #relayclose command, normal players are no longer able to login to the server.

This is thanks to the flow of our Sign In handler

PerpetuumServer/src/Perpetuum.RequestHandlers/SignInRequestHandler.cs

Lines 31 to 34 in bd606e2

	if (_relayStateService.State.Equals(RelayState.OpenForAdminsOnly) && !account.AccessLevel.IsAdminOrGm())
	{
	throw new PerpetuumException(ErrorCodes.RelayIsClosedForPublic);
	}

RelayClose, only closes it to the public (and not entirely for everyone) by setting the RelayState as such:

PerpetuumServer/src/Perpetuum.RequestHandlers/RelayClose.cs

Line 17 in bd606e2

_relayStateService.State = RelayState.OpenForAdminsOnly;

Caveats

Closing the relay has zero effect on normal players who already passed the login screen -> Meaning if they are sitting on Character Select or is in game, they can continue playing.

This will only block new attempts to log on to the server.

How to test

Requires 2 game accounts
One that is a regular account, and one that is of accessLevel Admin (tool or game, either works)

Apply the changes from this PR, then run the server.

• Login with your regular account, as a sanity check. Logout again.
• Login with your Admin Account, and enter the game with a character.
• #secure a chat channel, and then run the #relayclose command.
• • The server should no longer accept logins from normal accounts
• Logout of Admin Account
• Attempt to login with a normal account.
• You should see "error_RelayIsClosedForPublic"
• Log back in on your Admin Account, and in a #secure chat channel run the #relayopen command.
• Logout of Admin Account
• Attempt a login from the normal account, you should successfully get in now.

[MikeJeffers]

Nice work :)