globalApp as global mixin does not contain latest state

[tonydisera]

Navigation.vue relies on globalApp to get the geneinfo service URL. This field initialized in GeneHome, but Navigation.vue shows geneinfoServer set to null. For now, the workaround is to use cohortModel.globalApp instead. My guess is that Vue.js makes a copy of global app when the mixin is created, so any updates to the class made after Vue.js has made the copy are not reflected in the state of the global property available to all Vue.js components.