Port lensing UI to DeckGL viewer

[thejohnhoffer]

• Investing how lensing plugin has already been implemented in DeckGL
• Port the "drag and drop" UI from Minerva 1.5
• Port "scale and opacity" UI to track the lens

[thejohnhoffer]

Lens should be able to render as flexibly as main image--
-- either from RGB (H&E) or from multi-channel (CyCIF)

Going forward, the H&E OME-TIFF should be a single sample RGB image

• In the long-term, the interior / exterior of the lens could pull from multiple ome-tiff files
• As a first step, it is okay for each view to pull from a single ome-tiff