CEITEC: creator name in calendar should be displayed as the creator of the least recent reservation req.

[Medzikarp]

changes need to take place on new shongo-ceitec git branch

• introduce new endpoint returning only creator's name of the least recent reservation req. in history
• refactor reserourceReservationRequestsConfirmationCalendar.jsp so that fetches the name based on paretResReqId
• check the calendar still works as intended