Use panic instead of errors inside the operator package

[systay]

Description

To simplify the code and remove most of the

if err != nil { return err }

lines we have, this PR uses panics and a panic handler instead of returning errors. This way we can write code that doesn't need to do error checking, which is more compact and easier to read.

The idea is to use the operator package as an API, and the panics only exist inside the package. Whenever we are returning something to the outside of the package, we transform the panics back into errors, so users of the operator package don't need to do anything different.

We still use errors in a couple of places in the operator package, for situations where the error is handled. The panics are only for errors that are failures we can't fix inside the package.

Related Issue(s)

Checklist

• "Backport to:" labels have been added if this change should be back-ported
• Tests were added or are not required
• Did the new or modified tests pass consistently locally and on the CI
• Documentation was added or is not required

Deployment Notes

[vitess-bot]

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[vmg]

LGTM. I think this makes the planner more legible. 👍