Chore: Making Account Signup Optional (#563)

Introduce new environment variable that lets you control account signups
ENABLE_ACCOUNT_SIGNUP :( true | false | api_only )
Fixes: #406

Co-authored-by: Pranav Raj S <pranavrajs@gmail.com>

app/javascript/dashboard/routes/auth/auth.routes.js

@@ -36,6 +36,7 @@ export default {
           path: 'signup',
           name: 'auth_signup',
           component: Signup,
+          meta: { requireSignupEnabled: true },
         },
         {
           path: 'reset/password',