Add to MRF settings and update Pleroma.Upload.Filter.Mogrify setting

• Adds MRF Activity Expiration setting
• Displays labels of groups of setttings
• Ability to add custom values in Pleroma.Upload.Filter.Mogrify setting

src/views/settings/components/inputComponents/SpecificMultipleSelect.vue

@@ -16,6 +16,8 @@
       :value="data[setting.key]"
       :data-search="setting.key || setting.group"
       multiple
+      filterable
+      allow-create
       class="input"
       @change="updateSetting($event, settingGroup.group, settingGroup.key, setting.key, setting.type)">
       <el-option value="strip" label="strip"/>