Better differentiation between errors and warnings

Description of the new feature / enhancement

I've seen some manifest errors being told to the author only in the form of a warning:

• https://github.com/microsoft/winget-cli/issues/5193 (indent)
• https://github.com/microsoft/winget-pkgs/pull/161398#issuecomment-2208158341 (Moniker)

And some other error that don't affect the operation of winget are not raised:

> winget validate --manifest <path_to_manifest>
清单验证成功。

VScode treats this as an "error".

Proposed technical implementation details

For those that would cause a Manifest-Validation-Error, we can prompt the author with a manifest validation fail.
For values that do not affect the correctness of the manifest, but are not necessary, we can prompt the author with "清单验证成功，但出现警告".

Start with the winget validate --manifest entry point and compare the indent, Moniker, and validation examples linked in the description. Define which manifest findings should fail validation versus produce a warning, then verify that errors are reported as failures and non-correctness issues produce a success-with-warning result.