now student staff and program manager flags can edit event detials

[MImran2002]

Issue Description

Fixes issue:
An issue number was not created this is a hot fix as the PMs who are also CELTS Student Staff cannot edit event details. When in the meeting the PMs cannot edit event details as when clicking the button it turns grey.
This also fixes the users (isPM & isStudentStaff) getting deny access into create event page.

Changes

• Updated canManageProgram(program) so CELTS Admins and CELTS Operations Team members can manage any program.
• CELTS Student Staff members can manage a program only if they are assigned as a manager for that specific program.
• Added managesProgram(program) to check whether a user manages a specific program.
• Kept isProgramManager as a general property for checking whether a user manages at least one program.
• Avoided using the general program manager cache for program-specific permission checks..

Testing

• Checkout the branch programDetailsBug
• make sure your user Zach Neil is a Program Manager and a Student Staff.
• Switch to Zach Neil and go to Program Details and click the event Details button.
• You will now be able to edit it.