add signal valve (#14830)

Co-authored-by: deltanedas <@deltanedas:kde.org>

Resources/Textures/Structures/Piping/Atmospherics/pump.rsi/meta.json

@@ -5,7 +5,7 @@
       "y":32
    },
    "license":"CC-BY-SA-3.0",
-   "copyright":"Taken from https://github.com/tgstation/tgstation at commit 57cd1d59ca019dd0e7811ac451f295f818e573da",
+   "copyright":"Taken from https://github.com/tgstation/tgstation at commit 57cd1d59ca019dd0e7811ac451f295f818e573da. Signal valve is a digital valve modified by deltanedas.",
    "states":[
       {
          "name":"pumpDigitalValve",
@@ -19,6 +19,14 @@
          "name":"pumpManualValveOn",
          "directions":4
       },
+      {
+         "name":"pumpSignalValve",
+         "directions":4
+      },
+      {
+         "name":"pumpSignalValveOn",
+         "directions":4
+      },
       {
          "name":"pumpPassiveGate",
          "directions":4