[sim] Add SimDeviceSim ctor overloads (#3134)

Better parallelism with SimDevice.create(), so teams don't have to mess with concatenating the index/channel themselves.

wpilibj/src/main/java/edu/wpi/first/wpilibj/simulation/SimDeviceSim.java

@@ -28,6 +28,27 @@ public class SimDeviceSim {
     m_handle = SimDeviceDataJNI.getSimDeviceHandle(name);
   }
 
+  /**
+   * Constructs a SimDeviceSim.
+   *
+   * @param name name of the SimDevice
+   * @param index device index number to append to name
+   */
+  public SimDeviceSim(String name, int index) {
+    this(name + "[" + index + "]");
+  }
+
+  /**
+   * Constructs a SimDeviceSim.
+   *
+   * @param name name of the SimDevice
+   * @param index device index number to append to name
+   * @param channel device channel number to append to name
+   */
+  public SimDeviceSim(String name, int index, int channel) {
+    this(name + "[" + index + "," + channel + "]");
+  }
+
   /**
    * Get the property object with the given name.
    *