feat(settings): Allow to set the instances server location

Part-of: <https://dev.funkwhale.audio/funkwhale/funkwhale/-/merge_requests/2604>

front/src/components/admin/SettingsGroup.vue

@@ -217,6 +217,20 @@ const save = async () => {
           {{ v[1] }}
         </option>
       </select>
+      <select
+        v-else-if="setting.field.class === 'ChoiceField'"
+        :id="setting.identifier"
+        v-model="values[setting.identifier]"
+        class="ui search selection dropdown"
+      >
+        <option
+          v-for="v in setting.additional_data?.choices"
+          :key="v[0]"
+          :value="v[0]"
+        >
+          {{ v[1] }}
+        </option>
+      </select>
       <div v-else-if="setting.field.widget.class === 'ImageWidget'">
         <input
           :id="setting.identifier"

front/src/views/admin/Settings.vue

@@ -24,6 +24,7 @@ const groups = computed(() => [
     id: 'instance',
     settings: [
       { name: 'instance__name' },
+      { name: 'instance__location' },
       { name: 'instance__short_description' },
       { name: 'instance__long_description', fieldType: 'markdown', fieldParams: { charLimit: null, permissive: true } },
       { name: 'instance__contact_email' },