Add GSM::status() API

Author: sandeepmistry

src/GSM.cpp

@@ -385,3 +385,8 @@ int GSM::noLowPowerMode()
 {
   return MODEM.noLowPowerMode();
 }
+
+GSM3_NetworkStatus_t GSM::status()
+{
+  return _state;
+}

src/GSM.h

@@ -74,6 +74,8 @@ class GSM {
   int lowPowerMode();
   int noLowPowerMode();
 
+  GSM3_NetworkStatus_t status();
+
 private:
   GSM3_NetworkStatus_t _state;
   int _readyState;