adding backbone class and backbone base class

[triwahyuu]

Type of changes

Please check the type of change your PR introduces: - [ ] Bugfix - [x] Feature - [ ] Code style update (formatting, renaming) - [ ] Refactoring (no functional changes, no api changes) - [ ] Build related changes - [ ] Documentation content changes - [ ] Other (please describe): ## What is the new behavior?

• add backbone model base class
• add backbone class
• all defined backbones uses backbone base class

Checklist

• [x] Unit tests pass locally with my changes
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] I have added necessary documentation (if appropriate)
• [x] Any dependent changes have been merged and published in downstream modules
• [ ] I have filled the [Unreleased] Changelog

[triwahyuu]

all test errors would better be fixed in the next PR, since it is caused by breaking changes, and most of it is in detection models