Provide an Arbitrary Subsection Reporting widget to the Admin Dashboard

[scherztc]

Descriptive summary

This widget will allow the user to get the total number of Concerns by Content Type, Object, Creation Date, Embargo/Lease Date.

This widget will allow the user to get the total number of Files / File Sets by mime type or access.

Expected behavior

See the total number of objects (works) in the repository and a breakdown of the number of works by content type, organized and sortable by admin set name, object creation date, object publication date, and object embargo-release date, so that I can report on the volume, diversity, and growth over time of works in the repository

See the total number of the files in the repository, organized and sortable by MIME type, version number, and file-level access setting, so that I can report on the nature and diversity of files managed in the repository.