Changed websocket [secure] to endpoint selection.

[Jorropo]

This is for be compatible with libp2p/go-ws-transport#48 to allow websocket secure to be served under a real website (with reverse proxy) to go-libp2p.

To do:

• make ws transport compatible Changed to endpoint selection libp2p/js-libp2p-websockets#86
• make p2p-websocket-star transport compatible
• make p2p-webrtc-star transport compatible
• make multiaddr-to-uri compatible Websocket endpoint selection js-multiaddr-to-uri#4

[lidel]

I believe this is an example of generic need to specify/ovierride protocol-specific parameters. We discussed this recently from /http perspective (want to allow custom Host and path for use in DNS-over-HTTPS).

No consensus yet, but short summary/follow-up will be posted in multiformats/multiaddr#63 (comment)