Add slowdown to low temperatures (#29692)

* TemperatureSpeed component

* temperature slowdown prediction (done right)

* remove unnecessary changes

* that too

* get in line

* make it readonly

* auto pause

Content.Shared/Temperature/Components/TemperatureSpeedComponent.cs

@@ -0,0 +1,30 @@
+using Content.Shared.Temperature.Systems;
+using Robust.Shared.GameStates;
+
+namespace Content.Shared.Temperature.Components;
+
+/// <summary>
+/// This is used for an entity that varies in speed based on current temperature.
+/// </summary>
+[RegisterComponent, NetworkedComponent, Access(typeof(SharedTemperatureSystem)), AutoGenerateComponentState, AutoGenerateComponentPause]
+public sealed partial class TemperatureSpeedComponent : Component
+{
+    /// <summary>
+    /// Pairs of temperature thresholds to applied slowdown values.
+    /// </summary>
+    [DataField]
+    public Dictionary<float, float> Thresholds = new();
+
+    /// <summary>
+    /// The current speed modifier from <see cref="Thresholds"/> we reached.
+    /// Stored and networked so that the client doesn't mispredict temperature
+    /// </summary>
+    [DataField, AutoNetworkedField]
+    public float? CurrentSpeedModifier;
+
+    /// <summary>
+    /// The time at which the temperature slowdown is updated.
+    /// </summary>
+    [DataField, AutoNetworkedField, AutoPausedField]
+    public TimeSpan? NextSlowdownUpdate;
+}