GREG-225: Gender not sent to server in all cases

The gender suggestion, if there is one, was not sent to the server. The value in the drop-down box was filled in with the suggestion, but the form wasn't, so the value was not sent.

frontend/src/routes/guest/register/steps/register.tsx

@@ -239,6 +239,13 @@ const GuestRegisterStep = forwardRef(
       if (registerData?.mobilePhoneCountry) {
         setCountryCode(registerData.mobilePhoneCountry)
       }
+
+      if (gender !== '') {
+        // Need to set gender in the state and also in the form. This is
+        // to handle the case where the gender is suggested by the
+        // national ID number
+        setValue('gender', gender)
+      }
     }, [registerData])
 
     register('mobilePhoneCountry')