Analysis Histogram editing/download

[LTDakin]

Allow for edits to the histogram in the analysis page that are available to be downloaded. Images edited in this way will not be stored.

• add histogram slider to the analysis view
• get the slider to begin live changes on a temp img
• once the image is able to be changed with the slider, replace it in the leaflet map, and make sure that leaflet is happy with an imageOverlay that could be being set 100s of times
• disconnect fetching source catalog from loading a new image, only on first load if there's an image, don't want it to get a source catalog each time the image is updated since it will just be color corrections, base-name check maybe?
• histogram flag is set that lets the download menu know that instead of using the normal jpeg download, it needs to generate a new jpeg with zmin/zmax values
• make sure that TIF works and is passed the new zmin/zmax values if they exist

[jnation3406]

In order to not store an output image with this histogram, we might want to just add a new dropdown item to the list of download as [fits, jpeg, scaled jpeg] where choosing scaled jpeg would open up the histogram edits on that image for you to select and then when you click okay it would send those the to backend generate the jpeg, and send a link to the frontend for you to download just the jpeg.

[LTDakin]

I'm thinking of changing the behavior of the download menu when a scaling is done. Currently the TIF is generated on the fly. If the user scales an image we could do the same for the jpeg as well. This way the user doesn't have to know the difference between the two options and just downloads their jpeg.