add: translate registry unauthorized error when running a private image (#2101)

[iwilltry42]

Ref #2101

With this change, ImageDetails will translate HTTP StatusCodes returned by registries to equivalent Kubernetes API Errors that we can interpret client-side to e.g. tell the user to run acorn login first before trying to run a private image.

ImageDetails is first in line to try to access the registry.

Old Text

As you can see in the issue text, there is not much common text that we could match on and I hope we don't mask any "Unauthorized" errors coming from somewhere else (that I cannot think of right now). Here are some things that we **could** do:

1. Catch the Unauthorized error server-side (by status code) and return a common error from there
2. Also match on the context (registry) in the error message + try to match more variable parts of the message

Checklist

• The title of this PR would make a good line in Acorn's Release Note's Changelog
• The title of this PR ends with a link to the main issue being address in parentheses, like: This is a title (#1216). Here's an example
• All relevant issues are referenced in the PR description. NOTE: don't use GitHub keywords that auto-close issues
• Commits follow contributing guidance
• Automated tests added to cover the changes. If tests couldn't be added, an explanation is provided in the Verification and Testing section
• Changes to user-facing functionality, API, CLI, and upgrade impacts are clearly called out in PR description
• PR has at least two approvals before merging (or a reasonable exception, like it's just a docs change)