Enhancement: Add Active Storage image thumbnails

[nueadkie]

Functionality for delivering photos as thumbnails was lost after transitioning from Paperclip to Active Storage for storing and delivering photos. Having the user download multiple full-sized photos that can be upwards of 50 MB in size when browsing the project list harms performance and increases usage of AWS, so thumbnails should be used for most purposes instead. The user should be able to click on a photo to see it in full size.

[nick4rivers]

@nueadkie if you got this under control you can close it. But, this is a good one to leave open if it should be addressed in the future.

[ybakos]

See #325