[ISSUE] workspaceClient.Users.ListAll hangs if no StartIndex & TotalResults are returned

[alexott]

Observed in 0.26.1 that if I'm using the following fixture in test:

	userListIdUsernameFixture = qa.HTTPFixture{
		Method:   "GET",
		Resource: "/api/2.0/preview/scim/v2/Users?attributes=id%2CuserName&count=100&startIndex=1",
		Response: iam.ListUsersResponse{
			Resources: []iam.User{
				{
					Id:       "id",
					UserName: "user@domain.com",
				},
			},
		},
		ReuseRequest: true,
	}

then workspaceClient.Users.ListAll hangs

It was found in the context of databricks/terraform-provider-databricks#2980

[mgyucht]

FYI: in the TF repo, I added https://github.com/databricks/terraform-provider-databricks/blob/master/qa/scim_fixtures.go to help set up fixtures more easily for TF.

Separately, in b3cdc97, we added support for higher-level mocking of the WorkspaceClient. Now you can just mock the SDK calls rather than the underlying requests on the network, which should make testing with the WorkspaceClient easier.