[FEATURE] Expose Peer Certificate Info in TLS Sockets

Probably a long shot and outside the scope of workerd for now, but would be nice to have Web Workers API equivalent for [tls.TLSocket](https://nodejs.org/api/tls.html#class-tlstlssocket) from nodejs runtime. My particular use-case is being able to inspect peer certificate information like expiry date, TLS version and SN.

Feel free to close if it doesn't belong here