Update text in "Showing first 50 events" info box to encourage filtering

[minniewong]

Perhaps we should add a sentence to the "More than 50 events matched the current filter criteria." to suggest users to filter.

Update to "More than 50 events match the current filter. Click on the filter icon to narrow your search by date, event type and map view." or "More than 50 events match the current filter. Narrow your search by date, event type and map view."