Rename and port to Lomiri on focal

• port to Lomiri
• update Click packaging
• update Debian packaging for focal
• rename package and application by removing ubuntu- prefix
• adjust gallery and music app names
• remove snap packaging data
• update and move Jenkinsfile to debian/
• update translations

This fixes #172 (closed).

Current review errors:

- security:policy_groups_safe:camera:picture_files
(NEEDS REVIEW) reserved policy group 'picture_files': vetted applications only
- security:policy_groups_safe:camera:video_files
(NEEDS REVIEW) reserved policy group 'video_files': vetted applications only
- security:redflag_fields:camera.apparmor
found redflagged fields (needs human review): read_path

These have not changed.