feat: A license scanning support

[owenrumney]

Use https://github.com/google/licenseclassifier/tree/main/v2 to identify licenses in files

• add analyzer for license files
• add tests for analyzer
• add scanner for license files
• add tests for license scanner
• update misconfig to log and continue on scanner error
• ensure the License blobs make it into the cache and back out

Contributes to https://github.com/aquasecurity/trivy/issues/2303

Signed-off-by: Owen Rumney owen.rumney@aquasec.com