Ensure standardise CLI and plugin have identical behaviour

[cpelley]

This is motivated by our desire to define new configurations that don't go via the IMPROVER CLI at all. Doing so requires the behaviour to be identical between the CLI layer and calling plugins directly.

We remove logic currently held in the standardise CLI layer. In this case, it wasn't moved to the standardise plugin, but instead removed entirely (update_stage_v110_metadata) as per feedback.

https://github.com/MetOffice/barebones_workflow/pull/41 is dependent on this PR

Issues

• https://github.com/MetOffice/barebones_workflow/issues/32
• https://github.com/MetOffice/improver_suite/issues/2253
• https://github.com/MetOffice/improver_suite/issues/2079

[cpelley]

I have opted for a ~minimal change so as to aid getting this merged and ensuring backwards compatibility (at least until we cannot continue to do so).

• Reverted CLI standardise removal (retaining backwards compatibility with current science configurations).
• Reverted new "verbose" arguments to plugins (I needn't impose/drive this in this PR).

[cpelley]

Based on feedback, I have now opted for removing all the previous changes

• os.mkdir is now done within the Save plugin which lives alongside the science configuration as would save logic eventually...
• json load is now done on construction of the science configuration (settings) and is no longer the responsibility of IMPROVER.

This PR now only concerns itself with the issue of dealing with update_stage_v110_metadata. Therefore I have opted for its removal based on feedback by @bayliffe in the above comment. Nice and simple 😋

[cpelley]

Incorporated this CLI change into https://github.com/metoppv/improver/pull/2000 to ensure consistent approach.