port dotnet cataloger to new generic cataloger pattern (#1286)

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

syft/pkg/cataloger/dotnet/package.go

@@ -0,0 +1,55 @@
+package dotnet
+
+import (
+	"strings"
+
+	"github.com/anchore/packageurl-go"
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/anchore/syft/syft/source"
+)
+
+func newDotnetDepsPackage(nameVersion string, lib dotnetDepsLibrary, locations ...source.Location) *pkg.Package {
+	if lib.Type != "package" {
+		return nil
+	}
+
+	fields := strings.Split(nameVersion, "/")
+	name := fields[0]
+	version := fields[1]
+
+	m := pkg.DotnetDepsMetadata{
+		Name:     name,
+		Version:  version,
+		Path:     lib.Path,
+		Sha512:   lib.Sha512,
+		HashPath: lib.HashPath,
+	}
+
+	p := &pkg.Package{
+		Name:         name,
+		Version:      version,
+		Locations:    source.NewLocationSet(locations...),
+		PURL:         packageURL(m),
+		Language:     pkg.Dotnet,
+		Type:         pkg.DotnetPkg,
+		MetadataType: pkg.DotnetDepsMetadataType,
+		Metadata:     m,
+	}
+
+	p.SetID()
+
+	return p
+}
+
+func packageURL(m pkg.DotnetDepsMetadata) string {
+	var qualifiers packageurl.Qualifiers
+
+	return packageurl.NewPackageURL(
+		packageurl.TypeDotnet,
+		"",
+		m.Name,
+		m.Version,
+		qualifiers,
+		"",
+	).ToString()
+}