fix(rails): rider flags default to the RailActivatorComponent row

StartRailMovement's bDamageImmune, bNoAggro and bShowNameBillboard came
only from the level keys rail_activator_damage_immune, rail_no_aggro and
rail_show_name_billboard, which 23 of the 80 level rails do not have, so
those rails sent false. The client reads the same flags from the
RailActivatorComponent row (DamageImmune, NoAggro, ShowNameBillboard; all
11 rows are 1) in LWOPlayerForcedMovementComponent::LoadRailData
(0x00c85dc0), and the message's values replace the row's unless bUseDB
(msgStartRailMovement 0x00ccd9c0). The server now takes the row's value
and lets a level key replace it when the key is there. Wire format is
unchanged; only the flag values sent for the 23 rails change (to true,
matching the 5 live samples).

In game: ride the 23 rails without the keys, all in the Ninjago earth gauntlet
(earthgauntlet levels: dart spinners, 8 spinners, millstones, boss) near enemies: you are not
damaged or targeted while riding, and name billboards behave as on the
other rails.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

dGame/dComponents/RailActivatorComponent.h

@@ -36,6 +36,10 @@ public:
 	 * @param originator the entity that triggered the event
 	 */
 	void OnCancelRailMovement(Entity* originator);
+
+	bool GetDamageImmune() const { return m_DamageImmune; }
+	bool GetNoAggro() const { return m_NoAggro; }
+	bool GetShowNameBillboard() const { return m_ShowNameBillboard; }
 private:
 	/**
 	 * The entities that are currently traversing the rail