Remove site specific code from Horace

[nickbattam-tessella]

The Horace/Herbert code base includes code paths specifically for the iDAaaS deployment via an is_idaaas() function.

Site-specific code should not be included in the core Horace/Herbert code - this creates a situation where sites other than ISIS have a different deployment and user experience.

Where there are site-specific or machine-class-specific requirements (e.g. temp folder locations) these should managed through configuration data deployed in a consistent method. Configuration in a site-specific configuration file should override the default configuration.