feat(cpp): add base CppTree interface

[Divyateja2709]

hi @n1ckl0sk0rtge

This PR adds the base CppTree interface for upcoming C/C++ language support.

Changes Included

• Added CppTree.java under engine/src/main/java/com/ibm/engine/language/cpp/tree/
• Introduced the base tree type used as the engine's T generic parameter for C/C++
• Added basic node metadata methods for kind, line, and column

Purpose

CppTree provides the shared base interface for future C/C++ AST node types such as literals, identifiers, function calls, member access, and blocks.

[san-zrl]

Hi @Divyateja2709,

Thank you for your PR and for the time and effort you put into contributing to CBOMkit—we truly appreciate your interest.

You may have noticed that we are already working on adding C/C++ support to sonar-cryptography in PR #377. This approach differs from yours, as it relies on Sonar’s native C/C++ support package rather than ANTLR, similar to how the existing Java module is implemented.

Work on PR #377 is already quite advanced, and at this stage we are leaning toward this approach because we expect it to provide stronger support for cross-file symbol tracing through the Sonar infrastructure.

That said, we will keep your PR open for now until a final decision is made.