Reorganize project modules structure (gradle)

[Dymeth]

See:

• https://docs.gradle.org/8.5/userguide/structuring_software_products.html
• https://melix.github.io/blog/2021/12/composition-in-gradle.html
• https://docs.gradle.org/current/samples/sample_convention_plugins.html
• https://discuss.gradle.org/t/45077