Initiate magnetometer based compass calibration from button presses (#5553)

* Initiate magenetometer based compass calibration from button presses

- only active for BMX160 accelerometers on RAK_4631
- replace automatic calibration on power on with button triggered
  calibration
- set 5 presses to trigger 30s calibration
- set 6 presses to trigger 60s calibration (useful if unit is not
  handheld, ie vehicle mounted)
- show calibration time remaining on calibration alert screen

* Fix non RAK 4631 builds

- exclude changes from non RAK 4631 builds
- remove calls to screen when not present

* Fix build on RAK4631_eth_gw

- exclude all compass heading updates on variant without screen

---------

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/motion/MotionSensor.h

@@ -40,6 +40,8 @@ class MotionSensor
     // Refer to /src/concurrency/OSThread.h for more information
     inline virtual int32_t runOnce() { return MOTION_SENSOR_CHECK_INTERVAL_MS; };
 
+    virtual void calibrate(uint16_t forSeconds){};
+
   protected:
     // Turn on the screen when a tap or motion is detected
     virtual void wakeScreen();
@@ -53,6 +55,10 @@ class MotionSensor
 #endif
 
     ScanI2C::FoundDevice device;
+
+    // Do calibration if true
+    bool doCalibration = false;
+    uint32_t endCalibrationAt = 0;
 };
 
 namespace MotionSensorI2C