add layer contents display with searching

What's Changed

• add lint support by @rchamarthy in #4
• feat: add fetch-tags by @rchamarthy in #5
• make: move ociv back to default by @mikemccracken in #6
• WIP: add a layers subtree for image layers by @mikemccracken in #7
• better layer contents caching, squash support by @mikemccracken in #8

New Contributors

• @rchamarthy made their first contribution in #4

Full Changelog: v1.6...v1.7