Fix the tests after introducing the Setting

This recent introduction of the Settings model breaks the tests. One need to pass a setting object to the commute methods.

In the test we use the DEFAULT_SETTINGS (used in the store)

But importing any store from the tests is cumbersome as all the views are loaded and the import breaks when loading src/layout/MainNavbar.vue (due to unrecognized tag) So I've extracted this DEFAULT_SETTINGS constant in a dedicated file (src/store/constant.js)