feat: add gaz pulses simulation according to grdf opendata

codec/simugaz.js

@@ -0,0 +1,10 @@
+function decodeUplink(input) {
+    const b = input.bytes;
+    const pulses = (b[0] << 24) | (b[1] << 16) | (b[2] << 8) | b[3];
+    return {
+        data: {
+            pulse_count: pulses,
+            index_m3:    (pulses * 0.010).toFixed(3)
+        }
+    };
+}