Add more integration tests for the lib

[Luni-4]

We should add more integration tests for the languages we are already providing in the lib

[Luni-4]

We could create a data directory containing a subdirectory for each programming language. Then, in each of this subdirectories, it is present a repository of a medium-size project. For example:

• data/javascript ---> pdf.js
• `data/cpp --> deepspeech
• data/rust ---> grcov

and so on

Each repository is pinned to a specific version and they are treated as git submodules.

The tests directory contains an integration test for each subdirectory and it can verify different properties:

• See whether the metrics are computed and their comparison is correct
• See if a project does not contain error nodes

[Luni-4]

#724 added integration tests for the following languages:

• Rust
• JavaScript
• C/C++

Other integration tests need to be added:

• [ ] Java
• [ ] TypeScript
• [ ] Python