Add arrivals (#14755)

* Arrivals

* More arrivals and shitty uhh preload

* cvar

* a

* clockin + maps

* shitter prevention

* Placement

* a

* cvar for tests and dev

* weh

Content.Server/Shuttles/Events/FTLStartedEvent.cs

@@ -0,0 +1,9 @@
+using Robust.Shared.Map;
+
+namespace Content.Server.Shuttles.Events;
+
+/// <summary>
+/// Raised when a shuttle has moved to FTL space.
+/// </summary>
+[ByRefEvent]
+public readonly record struct FTLStartedEvent(EntityUid? FromMapUid, Matrix3 FTLFrom, Angle FromRotation);