Simplify CLI option handling #1932
Description
What would you like to be added:
A common way to collect and handle flags for configuration.
Currently flags names are in runner.go and their defaults are in server.go.
Deprecating flags (e.g., when moved to configuration) is also ad-hoc.
See #1911 for example.
Why is this needed:
Simplify and centralize flag handling so it is easier to find which flags exist, set their defaults and deprecate them in one place.
Ideally follow common Kubernetes practices of options.go