Add access to the adv type of remote device

Adds new method `uint8_t NimBLEAdvertisedDevice::getAdvType()`
to get the advertisement type of the found device.

src/NimBLEAdvertisedDevice.cpp

@@ -62,6 +62,16 @@ NimBLEAddress NimBLEAdvertisedDevice::getAddress() {
 } // getAddress
 
 
+/**
+ * @brief Get the advertised type.
+ *
+ * @return The advertised type of the advertised device.
+ */
+uint8_t NimBLEAdvertisedDevice::getAdvType() {
+    return m_advType;
+} // getAddress
+
+
 /**
  * @brief Get the appearance.
  *