WBL Events - Add a way for employers to "sign-up" to offer WBL Events for a certain date/time

For instance, this would allow an employer to volunteer to meet with students on a specific date/time and then any interested students could register to attend.

This would be even more valuable if scheduled WBL Events were shown to students as noted in this feedback item: https://feedback.eduready360.com/p/when-creating-a-wbl-event-add-an-option-to-allow.