[FEATURE] Better error reporting when no host parameter is provided

[alexott]

Problem Statement

We have multiple issues reported to the Terraform provider (i.e., databricks/terraform-provider-databricks#4113 just as one example) where default auth: cannot configure default credentials error is reported because host isn't set (eager resource creation by Terraform, or resource recreation, etc.). But it's very hard to understand what is wrong for unexperienced people.

Proposed Solution

When reporting such an error, check that host is specified in either form, and if it's missing, then provide a helpful message saying that the host is required and point to a troubleshooting guide or something like that.