CCM-10424 Fix link and remove import

Author: nicki-nhs

frontend/src/__tests__/app/create-letter-template/client-id-and-campaign-id-required/__snapshots__/page.test.tsx.snap

@@ -33,7 +33,7 @@ exports[`ClientIdAndCampaignIdRequiredPage 1`] = `
         <p>
           <a
             data-testid="back-to-choose-template-type-link"
-            href="/templates/choose-a-template-type"
+            href="/choose-a-template-type"
           >
             Go back
           </a>

frontend/src/components/molecules/InvalidConfig/InvalidConfig.tsx

@@ -3,7 +3,6 @@
 import { NHSNotifyMain } from '@atoms/NHSNotifyMain/NHSNotifyMain';
 import { InsetText } from 'nhsuk-react-components';
 import content from '@content/content';
-import { getBasePath } from '@utils/get-base-path';
 import Link from 'next/link';
 
 const { pageHeading, text, insetText, backLinkText } =