allow using DATABRICKS_AAD_TOKEN

[Synasenn]

Hi,

We recently switched to using a service principle and Azure AD token instead of using a PAT.
However this is causing errors in Nutter as it is hardcoded to use the DATABRICKS_TOKEN, which we no longer use.

could you please add the option to use the Azure AD token?

Also, is the usage of DATABRICKS_HOST and DATABRICKS_TOKEN variables actually needed? Can't it use the databricks cli with the configuration I made in an earlier step in our devops pipeline?