detect license ID from full text when incidentally provided as a value (#3876)

---------
Signed-off-by: Christopher Phillips <32073428+spiffcs@users.noreply.github.com>
Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>
Co-authored-by: Alex Goodman <wagoodman@users.noreply.github.com>

internal/licenses/find_evidence.go

@@ -0,0 +1,36 @@
+package licenses
+
+import (
+	"context"
+	"io"
+)
+
+func (s *scanner) FindEvidence(_ context.Context, reader io.Reader) (evidence []Evidence, content []byte, err error) {
+	if s.scanner == nil {
+		return nil, nil, nil
+	}
+
+	content, err = io.ReadAll(reader)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	cov := s.scanner(content)
+	if cov.Percent < s.coverageThreshold {
+		// unknown or no licenses here
+		// => check return content to Search to process
+		return nil, content, nil
+	}
+
+	evidence = make([]Evidence, 0)
+	for _, m := range cov.Match {
+		evidence = append(evidence, Evidence{
+			ID:    m.ID,
+			Type:  m.Type,
+			Start: m.Start,
+			End:   m.End,
+			IsURL: m.IsURL,
+		})
+	}
+	return evidence, content, nil
+}