Try to infer the edition from the path

For a `contentApiQuery` defined for a specific path, we always use `Edition.defaultEdition`. We should be at least trying to infer what the edition might be.

So we try, and if we don't know, we use the default.


@stephanfowler @ironsidevsquincy 
~~This means before this PR, requests out to anything other than `/uk`, `/us` and `/au` had the `defaultEdition` in its query. The `defaultEdition` being `Edition.UK`.~~

Although the above is true, as the `ContentApiClient` needs an edition, there is another step. We override the edition with what is in the `contentApiQuery` string, after setting it to `defaultEdition`. That means this PR will change nothing. But it is still better behaviour. Thanks @ironsidevsquincy !