chore: deprecate planName and version flags, remove planId validation - #1540

PR lgtm from a technical stand point.
Do we see any chance to improve the UX of the current solution?

Before:

Error: the provided instance plan is not valid.

You provided plan ID "ffffffff-ffff-ffff-ffff-ffffffffffff", which is invalid.

For more details on the available plans, run:
  $ stackit redis plans

After:

Error: create Redis instance: 400 Bad Request, status code 400, Body: {"error":"Provision failed. no service offering found for plan_id=ffffffff-ffff-ffff-ffff-ffffffffffff","description":""}

I've checked the redis api docs, but sadly the errors are not defined in the spec in a way we could reliably use here. But the "Before" error message is quite nice. It's formatted and also hints at redis plans.

PR lgtm from a technical stand point. Do we see any chance to improve the UX of the current solution?

Before:

Error: the provided instance plan is not valid.

You provided plan ID "ffffffff-ffff-ffff-ffff-ffffffffffff", which is invalid.

For more details on the available plans, run:
  $ stackit redis plans

After:

Error: create Redis instance: 400 Bad Request, status code 400, Body: {"error":"Provision failed. no service offering found for plan_id=ffffffff-ffff-ffff-ffff-ffffffffffff","description":""}

I've checked the redis api docs, but sadly the errors are not defined in the spec in a way we could reliably use here. But the "Before" error message is quite nice. It's formatted and also hints at redis plans.

I don't think we can do anything without verifying the plan beforehand. If the API gave a different error code then yeah, but i wouldn't want to start parsing the error message to "prettify" it in specific cases.

Merging this branch will increase overall coverage