Port dav calendar settings page to Vue.js

- Drop reliance on deprecated global jQuery object.
- Allow testing user interactions.
- Use newer technology stack.

---

Test user interactions with the groupware dav settings

Add infrastructure to test Vue components:

- Use recommended libraries:

    - https://vuejs.org/v2/guide/testing.html#Recommendations
    - Use jest-dom for robust assertions on the DOM state
    - Use user-event to be more representative of user actions

- Code is transpiled by Jest, with the help of vue-jest.

Ignore test files for no-unpublished-import. Prevent ESLint from
flagging:

```
/home/runner/work/server/server/apps/dav/src/views/CalDavSettings.spec.js
Error:   1:24  error  "@testing-library/vue" is not published         node/no-unpublished-import
Error:   2:23  error  "@testing-library/user-event" is not published  node/no-unpublished-import
```

Signed-off-by: François Freitag <mail@franek.fr>

1 files changed, 23 insertions, 0 deletions

diff --git a/tests/jestSetup.js b/tests/jestSetup.js
new file mode 100644
index 00000000000..bf167fb04b2
--- /dev/null
+++ b/tests/jestSetup.js
@@ -0,0 +1,23 @@
+/**
+ * @copyright 2021 François Freitag <mail@franek.fr>
+ *
+ * @author François Freitag <mail@franek.fr>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+require("@testing-library/jest-dom");