Adds the thermo-electric generator (#18840)

* Basic TEG start.

Connects via node group.

* Basic TEG test map

* Sensor monitoring basics, TEG circulator flow

* Basic power generation (it doesn't work)

* More sensor monitoring work

* Battery (SMES) monitoring system.

* Sensor monitoring fixes

Make it work properly when mapped.

* Test map improvements

* Revise TEG power output mechanism.

Now uses a fixed supplier with a custom ramping system.

* TEG test map fixes

* Make air alarms and pumps open UI on activate.

* Clean up thermo machines power switch.

Removed separate Enabled bool from the component that always matched the power receiver's state.

This enables adding a PowerSwitch component to give us alt click/verb menu.

* TEG but now fancy

* Make sensor monitoring console obviously WiP to mappers.

* Vending machine sound, because of course.

* Terrible, terrible graph background color

* Examine improvements for the TEG.

* Account for electrical power when equalizing gas mixtures.

* Get rid of the TegCirculatorArrow logic.

Use TimedDespawn instead. The "no show in right-click menuu" goes into a new general-purpose component.

Thanks Julian.

* Put big notice of "not ready, here's why" on the sensor monitoring console.

* TryGetComponent -> TryComp

* Lol there's a HideContextMenu tag

* Test fixes

* Guidebook for TEG

Fixed rotation on GuideEntityEmbed not working correctly.

Added Margin property to GuideEntityEmbed

* Make TEG power bar default to invisible.

So it doesn't appear in the guidebook and spawn menu.

Content.Server/NodeContainer/NodeGroups/NodeGroupFactory.cs

@@ -1,4 +1,5 @@
 using System.Reflection;
+using Content.Server.Power.Generation.Teg;
 using Robust.Shared.Reflection;
 
 namespace Content.Server.NodeContainer.NodeGroups
@@ -61,5 +62,12 @@ namespace Content.Server.NodeContainer.NodeGroups
         Pipe,
         WireNet,
         Spreader,
+
+        /// <summary>
+        /// Group used by the TEG.
+        /// </summary>
+        /// <seealso cref="TegSystem"/>
+        /// <seealso cref="TegNodeGroup"/>
+        Teg,
     }
 }