Remove warning about Free fucntion shadowing Interface function

[davidBar-On]

Fixes #10155

Suggested solution for remove warning messages that Free functions shadow Interface functions.
As I wrote in this comment, it may be considered to extended the solution to other declaration types inside an Interface, such as struct and enum.

(Note: only after submitting the PR I noticed that the "good first issue" label was remove, so the PR may be redundant. As I hope that the changes are useful I keep the PR open.)

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[NunoFilipeSantos]

We will try to review it soon.

[ekpyron]

This would need a rebase, a changelog entry, and some brushing up of the test coverage would also be nice, but generally, we could merge this.

[TonyVernocchi]

I've reviewed the changes related to the new isParentInterface flag in AST.h and the updates in ASTJsonImporter.cpp and Parser.cpp. These modifications seem to effectively differentiate between interface and free functions, which should improve the handling of shadowing during parsing and analysis.

I have a question about potential edge cases. How does this approach handle situations where a free function might have the same name as an interface function and also inherit some of its modifiers? Are there any specific checks in place to avoid unexpected behavior in such scenarios?

Additionally, while the code changes seem well-implemented, including a few unit tests that specifically cover interface function shadowing could further strengthen the pull request.