Add children_packages m2m and rename resolved_to_package #1066

[tdruez]

1. Rename DiscoveredDependency resolved_to to resolved_to_package, and resolved_dependencies to resolved_from_dependencies for clarity and consistency.
2. Add children_packages and parent_packages ManyToMany field on the DiscoveredPackage model.
3. Add full dependency tree in the CycloneDX output.

We now have:

• DiscoveredDependency.for_package: The package that declares this dependency.
• DiscoveredDependency.resolved_to_package: The resolved package for this dependency. If empty, it indicates the dependency is unresolved.
• DiscoveredPackage.children_packages: List of direct dependency packages.
• DiscoveredPackage.parent_packages: List of direct parent packages.
• DiscoveredPackage.declared_dependencies: List of declared dependencies in this package.
• DiscoveredPackage.resolved_from_dependencies: List of dependencies resolved from this package.

You'll notice that field names are now explicit and consistent:

• *_package is a package instance
• *_packages is a package queryset
• *_dependency is a dependency instance
• *_dependencies is a dependency queryset

@pombredanne @AyanSinhaMahapatra @Hritik14 Please have a look at those changes and additions and let me know you thoughts.

[pombredanne]

Thanks! this looks great.
FWIW: I am not convinced that the parent/children name is the best, but I have no immediate alternative to offer... we could evolve this later

[AyanSinhaMahapatra]

@tdruez This looks great thanks! I will update my PR accordingly once this is merged.