Allow conversion of dependencies to binary targets

[albertodebortoli]

This PR allows the creation of Package.swift files using binary targets instead of local or remote dependencies.
This can be particularly useful when relying on cached dependencies in the form of XCFrameworks.

Quite a few changes were needed and I recommend reviewing the commit history.

PackageGenerator can now be called with a new --dependencies-as-binary-targets flag and some related options:

$ PackageGenerator generate-package \
--spec <PATH_TO_PACKAGE_SPEC> \
--dependencies <PATH_TO_DEPENDENCIES_FILE> \
--template <PATH_TO_STENCIL_TEMPLATE> \
--dependencies-as-binary-targets \
--relative-dependencies-path <REALTIVE_PATH_TO_FOLDER_CONTAINING_DEPENDENCIES_AS_XCFRAMEWORKS> \
--version-refs-path <PATH_TO_VERSION_REFS_FILE> \
--exclusions <DEPENDENCIES_TO_EXCLUDE_FROM_BINARY_TARGETS>

[akuzminskyi]

or even enum as it's only namespace

Suggested change

	final class DTOLoader {
	struct DTOLoader {

[akuzminskyi]

both if and else has similar code

result.append(
                    PackageDependency(
                        name: dependency.name,
                        type: .remote(tag: dependency.version)
                    )
                )

I would suggest to simplify:

let type = if ... {
  .local(hash: versionRef)
} else {
  .remote(tag: dependency.version)
}

result.append(
  PackageDependency(
    name: dependency.name,
    type: type
  )
)

[albertodebortoli]

There is a guard in the way. This is meant to stay like this for readability.

[akuzminskyi]

guard I think can stay in place

let type: Type
 if ... {
  guard ... { throw .... }
  type = .local(hash: versionRef)
} else {
  type = .remote(tag: dependency.version)
}

result.append(
  PackageDependency(
    name: dependency.name,
    type: type
  )
)

[albertodebortoli]

Pushed ac64d1d

[akuzminskyi]

Suggested change

	var result = [PackageDependency]()
	var result = Set<PackageDependency>()

and you don't need to convert it below to Set

[akuzminskyi]

let for properties

[akuzminskyi]

you can use join - [relativeDependenciesPath, dependency.name, ...].join()

[akuzminskyi]

guard?

[akuzminskyi]

imho, such a comparison is not quite unclear. would remove/replace to more descriptive sortByLenght.... because URL("-1.0") URL("10") what do we compare here?

[albertodebortoli]

It's a leftover. I'll remove it.