Save image enhancments

[BryonLewis]

resolves #1510

Requires #1526 to be merged first

• Adds imageEnhancements to the metadata mutable (this is metadata stored in the DIVEDataset Folder Metadata that can be modified by a user)
• On back-end and front-end put the required references to imageEnhancements so it can be properly saved and loaded
• There is a debounce method on saving the imageEnhancements so that endpoint isn't hammered during sliding or other changes. It makes it so once it is complete it will send the request to the save the updated parameters.
• Updated Loading for Media Views (Video, Image, Large-Image was already okay) to set the SVG filter if the data is not the default image.

[naglepuff]

LGTM!