The new mode allows changing the config for a period of time, which
allows trying the configuration and automatically rolling it back in case
if it doesn't work for example.
The mode can only be used with changes that can be applied without a
reboot.
When changed it doesn't write the configuration to disk, only changes it
in memory.
`--timeout` parameter can be used to customize the rollback delay.
The default timeout is 1 minute.
Any consequent configuration change will abort try mode and the last
applied configuration will be used.
Signed-off-by: Artem Chernyshev <artem.chernyshev@talos-systems.com>
Dry run prints out config diff, selected application mode without
changing the configuration.
Signed-off-by: Artem Chernyshev <artem.chernyshev@talos-systems.com>
