feat: use circular buffer's new persistence option for machine logs

[utkuozdemir]

Switch from the old machine log storage approach to using the new persistence feature in the go-circular: https://github.com/siderolabs/go-circular/pull/4

Implement a migration code to migrate from old format to the new format when a machine log buffer is initialized.

Move some hardcoded log buffer settings into config (CLI args).

Use a default jitter of 0.1 (10+-1 minutes).

Rework the CLI arg names to be consistent.

Closes siderolabs/omni#118.

[utkuozdemir]

/m

[utkuozdemir]

/m