fix: set error type and stack with universal instrumentation

[dali546]

What does this PR do?

With Universal Instrumentation error message, type and stack aren't being sent to Datadog, resulting in poor experience in the APM

There is a small issue related to the source of the error, as well as the stacktrace of the error originating from inside the datadog library. Any help would be appreciated

Motivation

To see a fully working integration

Testing Guidelines

Created a simple lambda function that returns an error, with universal monitoring enabled.

Additional Notes

Types of changes

• Bug fix
• New feature
• Breaking change
• Misc (docs, refactoring, dependency upgrade, etc.)

Checklist

• This PR's description is comprehensive
• This PR contains breaking changes that are documented in the description
• This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• This PR impacts documentation, and it has been updated (or a ticket has been logged)
• This PR's changes are covered by the automated tests
• This PR collects user input/sensitive content into Datadog

[purple4reina]

Hey @dali546, thanks a ton for your contribution. I'm taking a look at it now.

[purple4reina]

Based on these changes, a handler that returns an error used to look like

but now looks like

You can see, we now include the error type and stack trace.

Note that this PR does not implement error type and stack trace for functions that return status code 500 or those that panic.

[purple4reina]

Thanks again for your contribution @dali546! All looks great. I'm going to add a few tests and then I'll merge it.

[dali546]

Thank you @purple4reina , appreciate the review and support!

[purple4reina]

Closing in favor of #171. I don't have access to add commits to this branch, so I created a new one.