TOTP (#109)

Fix not telling the user about invalid totp passcodes when logging in

Add disabling totp authentication

Add totp passcode when logging in

Add totp settings

Add general post method function

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/frontend/pulls/109

src/models/totp.js

@@ -0,0 +1,11 @@
+import AbstractModel from './abstractModel'
+
+export default class TotpModel extends AbstractModel {
+	defaults() {
+		return {
+			secret: '',
+			enabled: false,
+			url: '',
+		}
+	}
+}