feat: public recipe access (#1610)

* initial public explorer API endpoint

* public API endpoint

* cleanup recipe page

* wip: init explorer page

* use public URLs for shared recipes

* refactor private share tokens to use shared page

frontend/pages/group/mealplan/planner.vue

@@ -247,6 +247,7 @@
                     print: true,
                     share: false,
                     shoppingList: true,
+                    publicUrl: false,
                   }"
                 />
               </v-card-actions>