New version of evitaLab is backward incompatible in terms of configuration

[novoj]

Problem is with configuration option: api.endpoints.lab.gui.preconfiguredConnections

Negotiated steps for correction:

• we remove evita-configuration.yaml line from configuration on classpath
• when this line is missing the initial configuration fetch will generate necessary API urls from api.exposedOn, and if not defined from local hostname (in other words uses first item in the system / grpc urls here: io.evitadb.externalApi.configuration.AbstractApiConfiguration#getBaseUrls)
• the line will stay documented and may be added on any of the project to bootstrap evitaLab connections manually if necessary

[lukashornych]

I think we should still mark this as breaking change because we'll remove the CLI property to define path for the evitaLab connections.

[lukashornych]

Interestingly enough, the GuiHandler already works with the api.exposedOn so I just removed the api.endpoints.lab.gui.preconfiguredConnections CLI property as we've discussed and documented new recommended configuration.

Now we just need to make sure that the api.exposedOn is correctly configured, but evitaDB itself should crash anymore.