Resolve "Adapt to state block map"

Closes #9 (closed)

include/gnss/sensor/sensor_gnss.h

@@ -102,22 +102,22 @@ inline bool SensorGnss::isEnuMapInitialized() const
 
 inline StateBlockPtr SensorGnss::getEnuMapTranslation() const
 {
-    return getStateBlockPtrStatic(3);
+    return getStateBlock("t");
 }
 
 inline StateBlockPtr SensorGnss::getEnuMapRoll() const
 {
-    return getStateBlockPtrStatic(4);
+    return getStateBlock("r");
 }
 
 inline StateBlockPtr SensorGnss::getEnuMapPitch() const
 {
-    return getStateBlockPtrStatic(5);
+    return getStateBlock("p");
 }
 
 inline StateBlockPtr SensorGnss::getEnuMapYaw() const
 {
-    return getStateBlockPtrStatic(6);
+    return getStateBlock("y");
 }
 
 inline const Eigen::Matrix3s& SensorGnss::getREnuEcef() const