fix: add null checks for event tracker

[EternalFlower]

getLastEventRankings returns null if there is no event data getHistoryData will set undefined and empty array if received null as data EventTrackerTableRow will check if rankingData is null, if null, print "N/A" instead

Description

Fixed issues with Event Tracker: Fixed problem with incomplete event data with event "Echo My Melody" (event 76) will cause the entire website to crash Fixed problem with lack of data causing the event tracker to stay in fetch mode for event 87 (Never Give Up Cooking!) caused by the API changes.

Related Issue

428

436

Motivation and Context

428 - Selecting Echo My Melody will crash the entire page, forcing the user to refresh

436 - Since the newer events have no data, the event tracker will stay in fetch mode and prevent the user from accessing older event data.

How Has This Been Tested?

• [x] Chrome (Desktop)
• [ ] Chrome (Mobile)
• [x] Firefox (Desktop)
• [ ] Firefox (Mobile)
• [ ] Safari (Desktop, optional)
• [ ] Safari (iPhone, optional)
• [ ] Safari (iPad, optional)

Screenshots (if appropriate):

[EternalFlower]

The event tracker is not stuck in fetching mode and can change the drop down.

Echo My Melody does not crash the website