Add email integration to be able to broadcast emails to all users.

Resolves #388

app/web/src/Routes.js

@@ -62,6 +62,7 @@ const Routes = () => {
         <Route path="/admin/subject-access-requests/{id}/edit" page={EditSubjectAccessRequestPage} name="editSubjectAccessRequest" />
         <Route path="/admin/subject-access-requests/{id}" page={SubjectAccessRequestPage} name="subjectAccessRequest" />
         <Route path="/admin/subject-access-requests" page={SubjectAccessRequestsPage} name="subjectAccessRequests" />
+        <Route path="/admin/email" page={AdminEmailPage} name="adminEmail" />
       </Private>
     </Router>
   )

app/web/src/pages/AdminEmailPage/AdminEmailPage.tsx

@@ -0,0 +1,41 @@
+import {useState} from 'react'
+import { useMutation } from '@redwoodjs/web'
+import { toast, Toaster } from '@redwoodjs/web/toast'
+
+const SEND_EMAIL_MUTATION = gql`
+  mutation sendEmailMutation($email: Email!) {
+  sendAllUsersEmail(input: $email) {
+    accepted
+  }
+}
+`
+
+const AdminEmailPage = () => {
+  const [subject, setSubject] = useState('')
+  const [body, setBody] = useState('')
+  const [sendEmailMutation] = useMutation(SEND_EMAIL_MUTATION, {
+    onCompleted: ({sendAllUsersEmail}) => {
+      toast.success(`Emails sent, ${sendAllUsersEmail?.accepted.join(', ')}`)
+      setSubject('')
+      setBody('')
+    },
+  })
+
+  const sendEmail = () => sendEmailMutation({ variables: { email: { subject, body } } })
+
+  return (
+    <div className="flex justify-center">
+      <div className="max-w-7xl pt-8">
+        <h2 className="" style={{width: '46rem'}}>Email all users</h2>
+        <label htmlFor="subject">Subject</label>
+        <input name="subject" className="rounded border border-gray-400 px-2 w-full" value={subject} onChange={({target}) => setSubject(target.value)}/>
+        <label htmlFor="body">Body</label>
+        <textarea className="w-full rounded border border-gray-400 p-2" name="text" value={body} onChange={({target}) => setBody(target.value)}></textarea>
+        <button className="rounded px-2 p-1 mt-4 bg-ch-purple-400 text-indigo-200" onClick={sendEmail}>Send</button>
+      </div>
+      <Toaster timeout={1500} />
+    </div>
+  )
+}
+
+export default AdminEmailPage