🎉 Add Nextcloud widget

Add a widget supporting the `capabilites`, `user`
and `serverinfo` Nextcloud APIs.

Basic branding, user and quota information is always displayed
and when the provided credentials are for and admin user then
server information is also displayed.

APIs:
* [capabilities](https://docs.nextcloud.com/server/latest/developer_manual/client_apis/OCS/ocs-api-overview.html#capabilities-api)
* [user](https://docs.nextcloud.com/server/latest/developer_manual/client_apis/OCS/ocs-api-overview.html#user-metadata)
* [serverinfo](https://github.com/nextcloud/serverinfo)

src/components/Widgets/WidgetBase.vue

@@ -321,6 +321,13 @@
         @error="handleError"
         :ref="widgetRef"
       />
+      <NextcloudInfo
+        v-else-if="widgetType === 'nextcloud-info'"
+        :options="widgetOptions"
+        @loading="setLoaderState"
+        @error="handleError"
+        :ref="widgetRef"
+      />
       <PiHoleStats
         v-else-if="widgetType === 'pi-hole-stats'"
         :options="widgetOptions"
@@ -499,6 +506,7 @@ export default {
     NdLoadHistory: () => import('@/components/Widgets/NdLoadHistory.vue'),
     NdRamHistory: () => import('@/components/Widgets/NdRamHistory.vue'),
     NewsHeadlines: () => import('@/components/Widgets/NewsHeadlines.vue'),
+    NextcloudInfo: () => import('@/components/Widgets/NextcloudInfo.vue'),
     PiHoleStats: () => import('@/components/Widgets/PiHoleStats.vue'),
     PiHoleTopQueries: () => import('@/components/Widgets/PiHoleTopQueries.vue'),
     PiHoleTraffic: () => import('@/components/Widgets/PiHoleTraffic.vue'),