* Fix backup issue in network config modules
* Fix `get_working_path` not found issue introduced due to
backup config code refactor (PR #50208)
* Further refactor config related action plugins to minimize
duplicate code
* Remove unwated imports in config action plugins
* Add common network class for action plugin and related code refactor
* Fix review comment
- support config operations for EXOS-based platforms
- add regex to detect command failure responses
- add exos action plugin for "backup" operation
- add unit tests for exos_command (currently 94% coverage of
exos_config.py)
Ganesh Nalawade
Nathaniel Case
Martin Krizek
Lance Richardson