* Move keys into FreshDeskSettings class
* Add configurable custom fields for user and org
In FreshDesk we currently use the custom fields `cf_user` and `cf_org`.
- For the US instance these will be set to those values.
- For the EU instance these will likely be configured to `cf_user_eu` and `cf_org_eu`
* Fix file encoding
* Add region to notes
* Use customizable org field value in condition check
* Using correct ILogger on FreshdeskController
* Submitting custom fields to Freshdesk
* Set up FreshdeskController to use IHttpClientFactory
* Added unit test for FreshdeskController
* Moved ControllerCustomizeAttribute and ControllerCustomization to Common
* Modified FreshdeskController to use FreshdeskWebhookModel; Edited unit tests to use AutoFixture
