crane: Use `tarball` format insted of `legacy`

[cicharka]

• default format for crane is tarball now
• add optional legacy_format property to images.yml in order to let user chose which format should be used
• set insecure to False by default

[sonarcloud[bot]]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[seriva]

Closing as a new one will be created by @sbbroot fixing some of the comments.