package license detection lines are not correct

Also see related issue: https://github.com/nexB/scancode-toolkit/issues/2643

### Description

We should add offsets to the package license detection lines for them to be correct. Since we consider the extracted license statement alone, we make this as line 1

See the following results on scanning a single POM file which has both the file and package license detections, but the package license detections have incorrect line numbers.
[maxmind-db-1.3.1.pom-scan-results.json.txt](https://github.com/nexB/scancode-toolkit/files/11396605/maxmind-db-1.3.1.pom-scan-results.json.txt)