[hal] Add GetTeamNumber (#5596)

wpilibc/src/main/native/include/frc/RobotController.h

@@ -63,6 +63,13 @@ class RobotController {
    */
   static std::string GetComments();
 
+  /**
+   * Returns the team number configured for the robot controller.
+   *
+   * @return team number, or 0 if not found.
+   */
+  static int32_t GetTeamNumber();
+
   /**
    * Read the microsecond-resolution timer on the FPGA.
    *

wpilibc/src/main/native/include/frc/simulation/RoboRioSim.h

@@ -461,6 +461,31 @@ class RoboRioSim {
    */
   static void SetCPUTemp(units::celsius_t cpuTemp);
 
+  /**
+   * Register a callback to be run whenever the team number changes.
+   *
+   * @param callback the callback
+   * @param initialNotify whether to call the callback with the initial state
+   * @return the CallbackStore object associated with this callback
+   */
+  [[nodiscard]]
+  static std::unique_ptr<CallbackStore> RegisterTeamNumberCallback(
+      NotifyCallback callback, bool initialNotify);
+
+  /**
+   * Get the team number.
+   *
+   * @return the team number.
+   */
+  static int32_t GetTeamNumber();
+
+  /**
+   * Set the team number.
+   *
+   * @param teamNumber the new team number.
+   */
+  static void SetTeamNumber(int32_t teamNumber);
+
   /**
    * Get the serial number.
    *