fix(tracer): captureMethod detects proper method name when used with external decorators

[dreamorosi]

Description of your changes

In #1093 it has been reported that the tracer.captureMethod decorator was not properly detecting the name of the decorated class method, causing the name of the segment and the corresponding metadata entry to have an empty name.

I.e.

const tracer = new Tracer();

function passThrough() {
  // A decorator that calls the original method.
  return (_target: unknown, _propertyKey: string, descriptor: PropertyDescriptor) => {
    const originalMethod = descriptor.value!;
    descriptor.value = function (...args: unknown[]) {
      return originalMethod.apply(this, [...args]);
    };
  };
}

class MyClass {
  @tracer.captureMethod()
  @passThrough()
  async doSomething(): Promise<string> {
    return 'foo';
  }
}

const myClass = new MyClass();
await myClass.doSomething();

// Segment name will be "### "
/**
 * Metadata entry on the segment would be
 * {
 *   "default": {
 *     " response": "foo" <- key should have been `doSomething response`
 *   }
 * }
 *
 */

@misterjoshua, who opened the initial issue, also suggested a potential fix which was used in this PR.

This PR also adds an unit test case to demonstrate the fix.

How to verify this change

See new unit test case that was added in this PR.

Related issues, RFCs

Issue number: #1093

PR status

Is this ready for review?: YES
Is it a breaking change?: NO

Checklist

• My changes meet the tenets criteria
• I have performed a self-review of my own code
• I have commented my code where necessary, particularly in areas that should be flagged with a TODO, or hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding changes to the examples
• My changes generate no new warnings
• The code coverage hasn't decreased
• I have added tests that prove my change is effective and works
• New and existing unit tests pass locally and in Github Actions
• Any dependent changes have been merged and published in downstream module
• The PR title follows the conventional commit semantics

Breaking change checklist

N/A

---

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

[misterjoshua]

LGTM! Thanks for this.