esp_transport_list_t struct

Add a transport to the list, and define a scheme to indentify this transport in the list

Cleanup and free all transports, include itself, this function will invoke esp_transport_destroy of every transport have added this the list

Get the transport by scheme, which has been defined when calling function `esp_transport_list_add`

This function will remove all transport from the list, invoke esp_transport_destroy of every transport have added this the list