QoL Improvements for Media Importer

[clpetersonucf]

Based on a discussion about how H5P content is currently uploaded, and some general limitations of the importer, we discussed a few possible quality of life improvements:

• Direct uploads (like H5P content) should have their own, limited version of the interface
• Optional folder structure for media content browser: separated by the source widget (Labeling, Flash Cards, etc) or perhaps media type (image v audio)
• Optionally, some sort of hash check against existing assets to prevent many repeat uploads of the same media file