Separate API needed for Wallet from API needed for WabiSabi

[lontivero]

We should be able to host those apis in separate server or processes. For example, if we need to restart the index service we don't want to disrupt the coinjoin rounds.

[kristapsk]

First step would be to split to separate hostnames, like we did split of website vs api, now it would be to split api.walletwasabi.io to api.walletwasabi.io and somethingelse.walletwasabi.io. This needs changes in client and simple change in webserver config. Afterwards it can be split between multiple separate physical servers. Separate endpoints could be just proxied to different backends in nginx too, but separate hostnames removes one single point of failure.