EventPresentationModel: Cache the result of getBundledEvents()
EventPresentationModel: Cache the result of getBundledEvents()

Change-Id: I83ce3b7754055dd494fcde41f043144294da2f3f

wikimedia/mediawiki-extensions-Echo,wikimedia/mediawiki-extensions-Echo,wikimedia/mediawiki-extensions-Echo,wikimedia/mediawiki-extensions-Echo