Optimise the monthview and schedule view

This MR has several tweaks to improve the month view's performance:

• Added a refresh timer for the MultiDayIncidenceModel's model resetting, helping performance by reducing the number of consequent actions that this triggers.
• Swapped Control components for plain Items as the squares in the month view's grid, reducing component creation times.
• Simplified isNextItem boolean, reducing stuttering on month switch
• Previous and next month pages now load regardless of pathview movement -- since we load incidence model asynchronously, this helps eliminate most of the stutter while impacting start up times significantly less, plus also helps eliminate the overhead of deciding whether the loader is active or not
• Removed unused and expensive properties and optimised other properties
• Month grid now loads asynchronously, reducing stutter
• Events in the schedule view now load async, also reducing stutter