Point submit URLs *back* to the MFE for dev and the new submission page

Author: jmgasper

src/components/challenge-detail/Header/index.jsx

@@ -412,7 +412,7 @@ export default function ChallengeHeader(props) {
                   isLegacyMM
                 }
                 theme={{ button: style.challengeAction }}
-                to={`${config.URL.BASE}/challenges/${challengeId}/submit`}
+                to={`${challengesUrl}/${challengeId}/submit`}
               >
                 Submit
               </PrimaryButton>
@@ -422,7 +422,7 @@ export default function ChallengeHeader(props) {
                 hasSubmissions && (
                   <PrimaryButton
                     theme={{ button: style.challengeAction }}
-                    to={`${config.URL.BASE}/challenges/${challengeId}/my-submissions`}
+                    to={`${challengesUrl}/${challengeId}/my-submissions`}
                   >
                     View Submissions
                   </PrimaryButton>

src/components/challenge-detail/Submissions/index.jsx

@@ -734,7 +734,7 @@ class SubmissionsComponent extends React.Component {
               !hasRegistered || unregistering || submissionEnded || isLegacyMM
             }
             theme={{ button: style.challengeAction }}
-            to={`${config.URL.BASE}/${challengeId}/submit`}
+            to={`${challengesUrl}/${challengeId}/submit`}
           >
             Add Submission
           </PrimaryButton>