Treat normalized payload validation errors as warnings

[johanstokking]

Summary

Follow up on #5730
References #5429
References TheThingsNetwork/lorawan-devices#395

cc @pablojimpas

Changes

This changes the way field validation errors are treated. Before, the error was propagated to the caller and the entire payload wouldn't be considered normalized. This means that one out-of-bounds field renders the entire payload invalid. I think this isn't a nice developer experience: we should still not set these fields to out-of-bounds values but we should accept the rest of the fields and set the errors as warnings.

There's also a small unrelated change to see the normalized_payload{_warnings} in the payload simulation view.

Testing

CI and simulated uplink:

Regressions

None expected

Notes for Reviewers

• No need for changelog entry because this is still unreleased
• @kschiffer only review code owned files. I didn't add a code editor for the normalized payload. I think that would be nice though (although it's in the complete payload too), but just putting another editor in there didn't feel right UX wise so I'll leave this up to you. I consider this out of scope for this PR though

Checklist

• Scope: The referenced issue is addressed, there are no unrelated changes.
• Compatibility: The changes are backwards compatible with existing API, storage, configuration and CLI, according to the compatibility commitments in README.md for the chosen target branch.
• Documentation: Relevant documentation is added or updated.
• Changelog: Significant features, behavior changes, deprecations and fixes are added to CHANGELOG.md.
• Commits: Commit messages follow guidelines in CONTRIBUTING.md, there are no fixup commits left.

[kschiffer]

Changes look good. I wouldn't want to add something ad-hoc in here, so if you could create an issue for showing the normalized payload that would be great.