Add new action to toggle dwarf planet visibility (closes #2674)

data/assets/actions/trails/toggle_all_dwarf_planet_trails.asset

@@ -0,0 +1,35 @@
+local ToggleDwarfPlanetTrails = {
+  Identifier = "os.ToggleDwarfPlanetTrails",
+  Name = "Toggle dwarf planet trails",
+  Command = [[
+    local list = openspace.getProperty("{planetTrail_dwarf}.Renderable.Enabled")
+    for _,v in pairs(list) do
+      openspace.setPropertyValueSingle(v, not openspace.getPropertyValue(v))
+    end
+  ]],
+  Documentation = "Toggle on/off trails for all dwarf planets in the solar system",
+  GuiPath = "/Trails",
+  IsLocal = true
+}
+
+
+asset.onInitialize(function()
+  openspace.action.registerAction(ToggleDwarfPlanetTrails)
+end)
+
+asset.onDeinitialize(function()
+  openspace.action.removeAction(ToggleDwarfPlanetTrails)
+end)
+
+asset.export("ToggleDwarfPlanetTrails", ToggleDwarfPlanetTrails.Identifier)
+
+
+
+asset.meta = {
+  Name = "Actions - Toggle Dwarf Planet Trails",
+  Version = "1.0",
+  Description = "Asset providing actions to toggle all dwarf planet trails on and off",
+  Author = "OpenSpace Team",
+  URL = "http://openspaceproject.com",
+  License = "MIT license"
+}

data/assets/scene/solarsystem/dwarf_planets/pluto/pluto_trail_kepler.asset

@@ -28,7 +28,6 @@ local PlutoKeplerianTrail = {
     Resolution = 1000,
     Enabled = false
   },
-  Tag = { "planetTrail_dwarf" },
   GUI = {
     Name = "Pluto Keplerian Trail",
     Path = "/Solar System/Dwarf Planets/Pluto",