feat(gateway): enabling CORS * on gateway

[distractedm1nd]

Closes #2263

[Wondertan]

What about RPC? Did we check if it allows all the origins? The link we had was just for WS

[distractedm1nd]

@Wondertan I have not checked http over rpc, but the default connection for RPC should be ws://localhost anyways - since its the only transport that supports all of our endpoints. Adding in CORS for the (default) http client is pretty trivial but adds a lot of code (we are then no longer using the default http client so have to copy the rest of the default configuration to our client code)

[Wondertan]

My worry here comes from @smuu stating that RPC still didn't work because of CORS. Maybe because they used http and not ws?

[smuu]

My worry here comes from @smuu stating that RPC still didn't work because of CORS. Maybe because they used http and not ws?

I think we used HTTP, yes. I don't know why we didn't try ws.

[Wondertan]

I think we used HTTP, yes. I don't know why we didn't try was.

Likely because it not obvious, nor it's documented anywhere