Use a TLSOptions configuration object which is created via static
functions.
- "TLSOptions.client": uses the standard CA and common name verification.
- "TLSOptions.client_unsafe": uses optional CA verification (i.e. if specified)
- "TLSOptions.server": is the standard server configuration (chain + key)
This will allow us to expand the TLS configuration options to include
e.g. mutual authentication without bloating the classes that uses
StreamPeerTLS and PacketPeerDTLS as underlying peers.
