feat: module to ease cors configuration

[jeromevdl]

Issue #, if available:

Description of changes:

This module simplifies the configuration of CORS headers when using API Gateway and Lambda proxy. It removes boilerplate code in the function itself.

Checklist

• [x] Meet tenets criteria
• [x] Update tests
• [ ] Update docs => will do once code (and dev experience) is OK
• [x] PR title follows conventional commit semantics

Breaking change checklist

RFC issue #:

• [ ] Migration process documented
• [ ] Implement warnings (if it can live side by side)

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