refactor parsing restart-policies

[thaJeztah]

• relates to api/types/container: add RestartPolicyMode type and enum moby/moby#44704
• depends on vendor: github.com/docker/docker 5b53ddfcdd1c (v25.0.0-dev) #4534

---

• opts.ParseRestartPolicy: use a struct-literal and clarify that this
  function only parses, but does not validate invalid combinations.
• cli/compose/convert: convertRestartPolicy: update doc to be more
  clear on the order of preference and intent.
• cli/compose/convert: convertRestartPolicy: use a switch based on
  known values to allow the exhaustive linter to catch missing options.
• cli/compose/convert: convertRestartPolicy: add validation for negative
  values when converting the legacy service.restart policy.
• cli/compose/convert: convertRestartPolicy: always set MaxAttempts
  and leave validation to the daemon.

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 51.78571% with 27 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
cli/compose/convert/service.go	65.90%	12 Missing and 3 partials ⚠️
opts/parse.go	0.00%	12 Missing ⚠️

📢 Thoughts on this report? Let us know!

[thaJeztah]

⚠️ For reviewers; I'm leaning two ways on this PR;

• 👍 validate early
• 👎 there IS a potential (although unlikely that these combinations could be supported by a future API version
• 👍 then again, the CLI does not support "future" versions of the API
• 👍 and .. there's already code invalidating "unknown" restart policies
• 🤷‍♂️ so I guess this doesn't make things worse

[thaJeztah]

Honestly, I'm still a bit on the fence on this one, and not sure how much validation we can do on the client side (as "what's supported" may change on the daemon side, and even between API versions).

To some extent considering if we should go the reverse; just parse the general format, and let the daemon return errors where things are invalid.

[vvoland]

I'm kinda neutral here - even if we'd change anything, that would still be gated by the API version which would require a newer CLI anyway.

But on the other hand... We will have the error message even without it, so there's no real gain for the UX.

[vvoland]

@thaJeztah are we still considering this?

[thaJeztah]

I need to look at this one again; it's probably not urgent, so might be fine for later

[thaJeztah]

OK; I went the reverse: make the parsing more agnostic, and leave validation to the daemon side, except for the "stack" (compose file) conversion, because for those we still need to map "container" restart policies to "swarm" restart policies.