Fix rendering of events in Availability & refactor

- Possible dates were not ordered by dates, which in turn crashed
the rendering of Availability component
- Token was not added to headers after login
- Refactor Schedule by removing useless UseEffect
- Simplify rendering of events in Selected Dates (for now)

src/helpers/http-common.js

@@ -10,6 +10,7 @@ export const backend = axios.create({
 	},
 });
 
+// Add token if already in local storage
 if (existingToken) {
 	backend.defaults.headers.common['Authorization'] = JSON.parse(existingToken);
 }