Refactoring, cleanup

[kvaster]

• Separate running controller and node servers
• Allow to disable attacher - we do nothing on attach/detach to node it is really usefull
• Refactoring of helm chart:
  • Add liveness probe
  • Allow leader election for controller sidecars (replicas count is configurable now)
• Controller implements ControllerExpandVolume to only answer that node responsible for volume expansion
• Controller should be Deployment insteadof StatefulSet
• Driver support for gracefull shutdown
• Use SIGTERM for weed mount gracefull shutdown - SIGHUP is not processed.
• Cleanup staged volumes on shutdown
• Use golang 1.20
• Code refactoring & cleanup

[chrislusf]

Nice PR and a lot of work! Thanks! Is it possible to break into separate PRs? Or have the commit history for each change?

[kvaster]

I will try to split PR and keep commit history.

[kvaster]

I will make changes via several PRs and with commit history - I think I will do it much better such way. I will close this PR as soon as all necessary changes (new PRs) will be reviewed and accepted.