Fix course block instructor text when a course has more than one instructor.

[IsaDavRod]

• (Additional task for all courses, regardless of number of instructors) Only include instructor's last name for course blocks in calendar view instead of full name. If a course has two instructors, then separate last names by semicolon.

• For course blocks in Calendar View, ensure both instructor's last names are shown, separated by a comma.

• For course blocks in the Main Extension Popup, ensure both instructor's last names are shown, separated by a semicolon.

• For all course blocks in the Main Extension Popup, title-case instructor's last name instead of it being all capitalized

_{Huly®: UTRP-338}