* stage: extract unnecessary methods out of Stage class
* stage: change naming of functions
* stage: extract dump equal to utils
* stage: extract computation of md5 to utils
* stage: extract command run related logic in run.py
* stage: reorganize run()
* stage: boolean cosmetic changes
* stage: reorder save() and extract some into func
* stage: refactor status() into smaller functions
* extract resolve_wdir into utils
* merge _changed() and changed()
* cosmetic changes
* extract dump to utils
* extract import updates/sync to imports.py
* remove meta from PipelineStage
* fix imports, params load
* make run_stage a function, fix mocks in tests
* use original cmd
* rollback imports on decorators
* fix ds and cc
Saugat Pachhai
1676a7a1cd