Currently, the Socketpool/Socket API somewhat awkwardly crams two different libraries into the same implementation, using LWIP for non-encrypted TCP and datagrams, and the IDF/mbed TLS library for encrypted communication. Since TLS isn't really a transport layer library, it would be better to separate it into a different implementation of Socket, so the current Socket code doesn't need to infer what kind of socket it's dealing with for each call.

This is a follow up issue to PR #3854.