[IO-914][Internal] Also look for files ending in .JPG

[brentgracey]

d-py loops over known supported file extensions when "finding" images.

....JPG was not being found

Also look for files ending in .JPG

[linear]

IO-914 d-py: File has JPG (capital)

d-py loops over known supported file extensions when "finding" images.

001187a0-57ab-4329-baff-e7246a9edeb0___RS_Early.B 8178.JPG was not being found

[Nathanjp91]

We need to add tests for these edge cases, but this works as a fix for now as their aren't any existing tests and I won't put that burden on you. Other than that, LGTM. We do already have a function that automatically lower-cases file extensions to check if it's allowed, however this is the inverse, where the extension of the actual filename might be upper-cased. Will suggest in another ticket that resolve this in a non-hotfix manner, either parsing the annotation file for the filename (but keeping in mind that need to avoid opening the entire file for performance reasons if polygons are large) or by generating a more complete list of supported extensions with cases in mind.