Bump fullcalendar from 3.10.2 to 5.3.1

Bumps [fullcalendar](https://github.com/fullcalendar/fullcalendar) from 3.10.2 to 5.3.1.
- [Release notes](https://github.com/fullcalendar/fullcalendar/releases)
- [Changelog](https://github.com/fullcalendar/fullcalendar/blob/master/CHANGELOG.md)
- [Commits](https://github.com/fullcalendar/fullcalendar/compare/v3.10.2...v5.3.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -54,7 +54,7 @@
     "datatables": "^1.10.13",
     "easy-pie-chart": "^2.1.7",
     "file-loader": "^1.1.5",
-    "fullcalendar": "^3.6.2",
+    "fullcalendar": "^5.3.1",
     "jquery": "^3.2.1",
     "jquery-sparkline": "^2.4.0",
     "jvectormap": "^2.0.4",