Implement DNS module

[Jarred-Sumner]

TODO:

• lookup function on macOS
• resolve function on macOS
• reverse function on macOS
• lookup function on Linux
• resolve function on Linux
• reverse function on Linux
• Implement node:dns wrapper
• Decide on Bun.dns, bun:dns or otherwise what the API should be (cc @colinhacks who should probably make the decision)

Probably will ship once just lookup is done on Linux and macOS.

on macOS, we are using dnssd which is a builtin macOS library for multi-cast DNS. There is also an open-source version which can be used on Linux. We could use that.

[Jarred-Sumner]

Update: using dnssd seems like a no-go. DNSServiceGetAddrInfo takes around 10 seconds to timeout when the address is invalid and there is no way to set a timeout

Instead, I think we should try an approach like libuv/libuv#3509