[Admin Tools] Make it possible for admins to search for multiple copies of a file in all courses in a specific Sub Account.

[BarryLennon]

Problem statement:

Sometimes instructors or admins want to remove all instances of a specific file in multiple courses. Currently there is no way to search for multiple instances of the same file.

Proposed solution:

Make it possible to search for multiple instances of the same file across all courses in a Sub Account..

User role(s):

admin,instructor