Incorrect LookML URL returned when a different API URL used

[joshtemple]

When we construct the LookML URL for dimensions, we use the client-provided Looker base URL and the URL path returned from the Looker API (code).

For one user, this doesn't work because their API is hosted on a subdomain (e.g. api.looker.com). This means that all LookML URLs start with api., which is invalid and doesn't link to their project/instance. This means currently users have to remove api. from the start of the URL.

It's not clear what the best approach is here. We could provide an extra config option --api-url or --api-host for users with a different URL structure for their Looker API, ensuring we always use the actual instance URL for LookML URLs.

cc @DylanBaker who worked through this issue with the user in case I missed any details/considerations.