orchestrion: extend dd:span to support echo.Context

[korECM]

What does this PR do?

Motivation

Previously, the //dd:span integration was limited to functions that accepted a context.Context or *http.Request parameter. As many frameworks like Echo (using echo.Context) require additional handling, users had to add manual tracing.

This improvement specifically targets echo.Context support to streamline the process and reduce boilerplate code.

However, I do not believe that this approach is scalable. If you are considering extending the support of //dd:span to a broader range of function signatures, I would appreciate it if alternative methods could be discussed.

Related discussions:

• https://github.com/DataDog/orchestrion/discussions/539
• https://github.com/DataDog/dd-trace-go/discussions/3333

Reviewer's Checklist

• [ ] Changed code has unit tests for its functionality at or near 100% coverage.
• [ ] System-Tests covering this feature have been added and enabled with the va.b.c-dev version tag.
• [ ] There is a benchmark for any new code, or changes to existing code.
• [ ] If this interacts with the agent in a new way, a system test has been added.
• [ ] Add an appropriate team label so this PR gets put in the right place for the release notes.
• [ ] Non-trivial go.mod changes, e.g. adding new modules, are reviewed by @DataDog/dd-trace-go-guild.
• [ ] For internal contributors, a matching PR should be created to the v2-dev branch and reviewed by @DataDog/apm-go.