Add isRpa method to NimBLEAddress.

This provides and easy way to check if the peer address is a Resolvable Private Address.

src/NimBLEAddress.cpp

@@ -138,6 +138,15 @@ uint8_t NimBLEAddress::getType() const {
 } // getType
 
 
+/**
+ * @brief Determine if this address is a Resolvable Private Address.
+ * @return True if the address is a RPA.
+ */
+bool NimBLEAddress::isRpa() const {
+    return (m_addrType && ((m_address[5] & 0xc0) == 0x40));
+} // isRpa
+
+
 /**
  * @brief Convert a BLE address to a string.
  *