Get customer details by ID

{
    "customer": {
        "id": "c9a1f6c2-8c2b-4c91-9f7b-2e5b8b0d3a01",
        "firstName": "John",
        "lastName": "Doe",
        "companyName": "Acme Heating Services",
        "displayName": "John Doe - Acme Heating Services",
        "address1": "123 Main St",
        "address2": "Suite 200",
        "city": "Dallas",
        "state": "TX",
        "zip": "75201",
        "billingAddress1": "123 Main St",
        "billingAddress2": "Suite 200",
        "billingCity": "Dallas",
        "billingState": "TX",
        "billingZip": "75201",
        "primaryPhone": "+1-214-555-0198",
        "primaryEmail": "john.doe@acmeheating.com",
        "contactOnPhone": true,
        "contactOnSms": true,
        "contactOnEmail": true,
        "active": true,
        "billFromOffice": false,
        "parentCustomerId": "a7b2d1e3-5f89-4b1d-9a6e-2c9b8f2a0b44",
        "hasServiceAgreement": true,
        "agreementId": "sa-4e6d9b12-98a4-41e2-bc2f-91f3e61c3b55"
    }
}