feat(instrumentation-aws-lambda): take care of ESM based (.mjs) handlers

[serkan-ozal]

Which problem is this PR solving?

Currently, ESM based handlers with .mjs file extension are not taken care of by AWS Lambda instrumentation, but ESM based handlers are supported since long time (https://aws.amazon.com/tr/about-aws/whats-new/2022/01/aws-lambda-es-modules-top-level-await-node-js-14/).

Short description of the changes

For the fix, while handler file is being resolved, in addition to .js and .cjs file extensions, .mjs file extension is also checked.

This PR is the contrib counter part of the open-telemetry/opentelemetry-js#5094

[codecov]

Codecov Report

Attention: Patch coverage is 71.42857% with 2 lines in your changes missing coverage. Please review.

Project coverage is 90.77%. Comparing base (80d0c74) to head (c0be5ce).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...-instrumentation-aws-lambda/src/instrumentation.ts	71.42%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2508      +/-   ##
==========================================
- Coverage   90.79%   90.77%   -0.02%     
==========================================
  Files         169      169              
  Lines        8009     8015       +6     
  Branches     1632     1632              
==========================================
+ Hits         7272     7276       +4     
- Misses        737      739       +2     

Files with missing lines	Coverage Δ
...-instrumentation-aws-lambda/src/instrumentation.ts	93.60% <71.42%> (-0.98%)	⬇️

[raphael-theriault-swi]

Looks like a subset of #2000, thanks for addressing the issue in the instrumentation code wrt. absolute paths !

[trentm]

@pichlermarc I haven't merged this yet, in case OP would like to respond to my comments above. I think it is good to merge if you are doing a release that could include this tomorrow.

[trentm]

@raphael-theriault-swi Ah, sorry I hadn't seen your earlier PR ... and I hadn't really been digging into Lambda-related PRs. I'll try to take a look in the next few days.

[raphael-theriault-swi]

@trentm I'd just go with whatever is easier to review and get out of the doors, ultimately the important part is ESM support

[serkan-ozal]

@trentm Thanks for the review. I have updated PR according to your comments