Deploy `blockfrost-gateway` before the 0.0.3 release

[michalrus]

Context

We need to test the WebSocket integration before release a non-RC 0.0.3 version of the Platform.

How many instances?

We had a small confusion (Slack thread) with https://api-dev.icebreakers.blockfrost.io/ and WebSockets. It turned out that there were 2 instances deployed, and the system seemed to behave unsoundly.

We can have multiple instances, but we have to expose the /ws endpoint of each of them.

Then the Platforms can connect to each for high-availability.

And we still keep a single public ingress URL for endpoints like /stats or /:uuid/tx/submit etc.