Update the swagger api

[dmitrivenger]

Perhaps just copy the BlockFrost yaml as a way to document our API. We may remove the historical queries for the first release.

@lowhung please reference the PR here that resolves this issue. Thanks.

[lowhung]

API spec can be found below:
https://github.com/input-output-hk/acropolis/blob/main/API/openapi.yaml