Add ScheduleView / SessionGrid configurability

[robb-j]

In https://github.com/digitalinteraction/mozfest-client/pull/7 an intermediate FilteredScheduleView was added to make it easier to add multiple schedule views. Along with #70 the requirements for adding a custom schedule/grid page could be reduced and simplified.

• ScheduleView could be deprecated and a new SessionTimeline could be used instead, so as not to require a breaking change. It doesn't make sense to have View in the name anyway as it is not directly routed to from vue-router.
• SessionGrid could be deprecated and a new SessionBoard could be used instead, so as not to require a breaking change.

It would be worth considering a data-driven approach too so a CMS could be used to power these configurations in the future.

Configuration

Props

• schedule — The ScheduleRecord with all resources in it
• userSessions — The ids of sessions users have added to their schedule
• options — An object with structure below:

options

property	Info
tileConfig	#70 if it has been implemented, would create a blocker for this though
sessionPredicate	A function to decide wether to show this session or not
filtersKey	The localStorage key to store filters in
enabledFilters	Which filters to show, for ScheduleFilters.vue
languages	SelectOption-s of languages the sessions are in

SessionTimeline could also have a sessionLayout property that decides wether a given session should be "big" or "small" in the ScheduleBlock