Add separate size limit for objects in LFS
Description
We deploy GitLab EE in an educational environment, and will soon be offering dedicated workshops on how to use Git LFS for storing large binary objects, instead of adding them to the repository directly. The incentive for actually doing so is small though. The repository size is limited by a single option per repository, that includes LFS objects as well ("Size limit per repository" in Application Settings).
We'd like to be able to "encourage" students (and staff alike) to put Git LFS to use, and restrict the maximum repository size for regular Git storage and LFS storage separately. Thus, LFS could be set to a large repo limit, while regular Git storage is capped more strictly.
Proposal
Add a separate "Size limit for Git LFS objects" settings in the admin interface, and remove LFS objects from being included in "Size limit per repository"