add/process tree-specific photos

[emillipede]

AS A/AN:
user

WHEN I:
view a tree on the map

I WANT TO:
see the best possible photographic represenation of the tree

context
Dave Baoicchi photographed many of the city's heritage trees, as well as some other public sidewalk and park trees.

He offered them for use on the site. The photographs can serve the initial tree image for each tree, rather than an EOL image.

I now think it's important to set up this system in a way that's not specific to heritage trees but would work for any tree with a city-assigned ID. we may also get images from other sources in the future. for now, they're just from Dave For the heritage trees, I've begun to add his heritage tree imagery from flickr to the repository (not sure if the images should go in the pipeline data files), please see Public-Tree-Map/public-tree-map #99

As Dave requested, we'll link to his website in the manner we do with EOL.

[mrtmrt233]

I think either (putting these images in frontend or backend) works, but in the interest of resource organization, the backend route makes more sense.

[emillipede]

thank you for the input @mrtmrt233 I'll transfer this issue to the other repository