Unit tests: state tracking

[sskaur]

This issue is to keep track of unit tests related to state tracking (read/write to local and omap states).

• [ ] Test if local state dict is as expected after adding bdev
• [ ] Test if local state dict is as expected after removing bdev
• [ ] Test if local state dict is as expected after adding subsystem
• [ ] Test if local state dict is empty after adding all subsystem-related components (subsystem, namespace, host, & listener) and then removing the subsystem
• [ ] Test if delete_state resets contents of local state dict
• [ ] Test if local state dict is as expected after adding listener
• [ ] Test if local state dict is as expected after removing listener
• [ ] Test if local state dict is as expected after adding host
• [ ] Test if local state dict is as expected after removing host
• [ ] Test if local state dict is as expected after adding namespace
• [ ] Test if local state dict is as expected after removing namespace
• [ ] Test if omap is as expected after add_bdev (version number and omap contents)
• [ ] Test if omap is as expected after remove_bdev (version number and omap contents)
• [ ] Test if omap is as expected after add_subsystem (version number and omap contents)
• [ ] Test if omap is as expected after after adding all subsystem-related components (subsystem, namespace, host, & listener) and then remove_subsystem
• [ ] Test if omap is as expected after add_namespace (version number and omap contents)
• [ ] Test if omap is as expected after remove_namespace (version number and omap contents)
• [ ] Test if omap is as expected after add_host (version number and omap contents)
• [ ] Test if omap is as expected after remove_host (version number and omap contents)
• [ ] Test if omap is as expected after add_listener (version number and omap contents)
• [ ] Test if omap is as expected after remove_listener (version number and omap contents)
• [ ] Test if omap is empty after deleting contents