chore: Log requests to widget endpoints

[cmaddox5]

We have no logs for these endpoints in any environment but Mercury uses them to create images for the e-inks. Adding some logging so we have a way to tell when something goes wrong.

[digitalcora]

It looks like the assertion that we had no logs for these endpoints was my mistake — we do, in the sense that they're covered by the standard Phoenix request logs, and I just missed them in my searching. So, I'm not sure if adding this extra logging is valuable, but open to the suggestion.

[cmaddox5]

The existing logs may make the info log I added redundant, but I think having some visibility into bad requests would be helpful. I would be curious to see if an error indicates an issue on the screen so being notified of them could help answer that. What do you think?

[digitalcora]

Error logging sounds good — this is kind of an "exceptional" scenario rather than something we'd expect to hit regularly. If we want to be notified proactively about it, maybe a Sentry report instead? But I think just making it stand out a bit more in the logs is fine.