Taxonomy Term Zendesk Form

@sergii-tkachenko Can you review when you have a chance?

* Abstracts logic out of `dosomething_zendesk_form` into new function`dosomething_zendesk_get_zendesk_group_id`, to determine what Zendesk Group ID a ticket should be created for for a given loaded Entity object.

* Adds and outputs Zendesk Form on the Taxonomy Term page template.

* Adds `DOSOMETHING_ZENDESK_LOG` flag to make for easier debugging.