esp_netif: Introduction of esp-netif component as a replacement of tcpip_adpter

- provides object oriented access to network intefaces
- not limited to default netifs
- more generic abstraction to network input output functions
- event handler registration removed from component responsibility
- backward compatibility layer for legacy tcpip_apapter APIs

Closes IDF-39

components/lwip/port/esp32/include/netif/dhcp_state.h

@@ -24,7 +24,7 @@ bool dhcp_ip_addr_restore(void *netif);
 
 void dhcp_ip_addr_store(void *netif);
 
-void dhcp_ip_addr_erase(void *netif);
+void dhcp_ip_addr_erase(void *esp_netif);
 
 #ifdef __cplusplus
 }