We need an abstraction between TIdUDPBase and TIdSocketHandle for DTLS support

[JPeterMugaas]

I think we need a new component or components that can act as a layer between what is in TIdUDPBase classes and TIdSocketHandle for a class that can be used to make DTLS-aware descendant classes. Such a class could also provide a way to "socksify" or make the UDP client/server support the SOCKS protocol.

[rlebeau]

Indy already supports SOCKS for UDP clients via the TIdSocksInfo component. There is also a TIdSocksServer component, but it currently does not support UDP clients. In any case, TLS and SOCKS have nothing to do with each other, so let's keep those feature requests separate.