Add overnight events functionality and display to widget

[troughc]

Currently, the widget does not consider overnight events. It just shows the data it receives from the backend.
This means that the widget shows overnight events as a two date event rather than a single date event. Please see screenshots of test event below.

WIDGET VIEW - 2 days instead of single date (the event below my event (Jacques Falquet) is what i would expect to see in terms of date-time)

Expected behaviour: UI and UX is consistent with overnight events in main CMS. This means that is would display a single date and start-time.

for more information on overnight events and how to display, see culturecreates/footlight-app#1363

[SyamBabu-M]

@troughc I have added the estimate. I couldn't find the to-be-scheduled tag for this issue, so I haven't added it. Please let me know when I should start the work on this.

[troughc]

tested in staging: PASSED
@SyamBabu-M this is good to be deployed.