GET - https://subscribercrmapi.musiciansunion.org.uk/api/enquirysubcategory
Lists all Enquiry Sub Categories.
[ { "EnquirySubCategoryId": 1, "EnquiryCategoryId": 1, "Name": "Sub Category 1" }, { "EnquirySubCategoryId": 2, "EnquiryCategoryId": 1, "Name": "Sub Category 2" }]