feat: add --from flag, refactor source providers (#2610)

Signed-off-by: Keith Zantow <kzantow@gmail.com>

syft/linux/identify_release_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/anchore/syft/syft/source"
+	"github.com/anchore/syft/syft/source/directorysource"
 )
 
 func TestIdentifyRelease(t *testing.T) {
@@ -336,7 +337,9 @@ func TestIdentifyRelease(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.fixture, func(t *testing.T) {
-			s, err := source.NewFromDirectoryPath(test.fixture)
+			s, err := directorysource.New(directorysource.Config{
+				Path: test.fixture,
+			})
 			require.NoError(t, err)
 
 			resolver, err := s.FileResolver(source.SquashedScope)