[otelgin]: Catch and record panics in Middleware

[asecondo]

Problem Statement

Today, the otelgin middleware does not handle panics. In the event that there's some bug in some service code or lower middleware layer that panics, this information is not present in the resulting span. It would be incredibly useful to leverage this information to help troubleshooting in development and production environments.

Proposed Solution

Catch, record, and "rethrow" any panics. This solution would likely look very similar to the otelgin.HTML(...) handler here.

Alternatives

• Do nothing, as is currently done today
• Add panic recovery handling to this middleware. This feels incorrect, as we'd be going beyond the expected responsibilities of this middleware.

Prior Art

As mentioned above, we would likely leverage a similar solution used in the same package here.

Additional Context

N/A.