port php cataloger to new generic cataloger pattern (#1315)

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

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

syft/pkg/cataloger/php/package.go

@@ -0,0 +1,51 @@
+package php
+
+import (
+	"strings"
+
+	"github.com/anchore/packageurl-go"
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/anchore/syft/syft/source"
+)
+
+func newComposerLockPackage(m pkg.PhpComposerJSONMetadata, location ...source.Location) pkg.Package {
+	p := pkg.Package{
+		Name:         m.Name,
+		Version:      m.Version,
+		Locations:    source.NewLocationSet(location...),
+		PURL:         packageURL(m),
+		Language:     pkg.PHP,
+		Type:         pkg.PhpComposerPkg,
+		MetadataType: pkg.PhpComposerJSONMetadataType,
+		Metadata:     m,
+	}
+
+	p.SetID()
+	return p
+}
+
+func packageURL(m pkg.PhpComposerJSONMetadata) string {
+	var name, vendor string
+	fields := strings.Split(m.Name, "/")
+	switch len(fields) {
+	case 0:
+		return ""
+	case 1:
+		name = m.Name
+	case 2:
+		vendor = fields[0]
+		name = fields[1]
+	default:
+		vendor = fields[0]
+		name = strings.Join(fields[1:], "-")
+	}
+
+	pURL := packageurl.NewPackageURL(
+		packageurl.TypeComposer,
+		vendor,
+		name,
+		m.Version,
+		nil,
+		"")
+	return pURL.ToString()
+}