fix(middleware-recursion-detection): case-insensitive trace ID header detection in middleware

[smilkuri]

Issue

#6937

Description

Updates the recursion detection middleware to properly handle case insensitive matching of the X-Amzn-Trace-Id header.

Testing

How was this change tested?
Locally by adding unit test.

RUN  v2.1.9 /local/home/smilkuri/aws-sdk-js-v3/packages/middleware-recursion-detection

✓ src/index.spec.ts (5)
  ✓ recursionDetectionMiddleware (5)
    ✓ sets X-Amzn-Trace-Id header when function name and trace id environmental variables are set
    ✓ should NOT set X-Amzn-Trace-Id header when function name environmental variable is NOT set
    ✓ should NOT set X-Amzn-Trace-Id header when the header is already set
    ✓ should NOT set X-Amzn-Trace-Id header when the header is already set in all lowercase
    ✓ has no effect for browser runtime

Test Files  1 passed (1)
     Tests  5 passed (5)
  Start at  16:05:33
  Duration  315ms (transform 49ms, setup 0ms, collect 44ms, tests 4ms, environment 0ms, prepare 93ms)

---

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[kuhe]

"is already set in all lowercase" should be "is already set with some other casing"

add a couple of test cases with inconsistent casing like x-AmZn-TrAcE-iD

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs and link to relevant comments in this thread.