fix: index file itself when file scan path has symlink (#2359)

Previously, building the index of the filesystem when source was file
would fail if part of the path syft was passed to the file included a
symlinked directory, resulting in cataloging misses.

---------

Signed-off-by: Will Murphy <will.murphy@anchore.com>

test/cli/symlink_test.go

@@ -0,0 +1,13 @@
+package cli
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func Test_RequestedPathIncludesSymlink(t *testing.T) {
+	// path contains a symlink
+	path := "test-fixtures/image-pkg-coverage/pkgs/java/example-java-app-maven-0.1.0.jar"
+	_, stdout, _ := runSyft(t, nil, "packages", path)
+	assert.Contains(t, stdout, "example-java-app-maven")
+}