Implement basic virtual Room support based on enet (#2803)

* Added support for network with ENet lib,

connecting is possible, but data can't be sent, yet.

* fixup! Added support for network with ENet lib,

* fixup! CLang

* fixup! Added support for network with ENet lib,

* fixup! Added support for network with ENet lib,

* fixup! Clang format

* More fixups!

* Moved ENetHost* and ENetPeer* into pimpl classes

* fixup! Moved ENetHost* and ENetPeer* into pimpl classes

* fixup! Clang again

* fixup! Moved ENetHost* and ENetPeer* into pimpl classes

* fixup! Moved ENetHost* and ENetPeer* into pimpl classes

* fixup! Moved ENetHost* and ENetPeer* into pimpl classes