Better validation output messages for PackageIdentifier schema issues

Description of the new feature / enhancement

When I use winget validate with a PackageIdentifier that does not meet the schema, the output looks like this:

> winget validate .\RemoteToolsForVisualStudio2022\Latest
Manifest validation failed.
Manifest Error: Schema Error. [Schema validation failed.
Error context: <root>[PackageIdentifier] Description: Failed to match regex specified by 'pattern' constraint.
Error context: <root> Description: Failed to validate against schema associated with property name 'PackageIdentifier'.
] File: Microsoft.RemoteToolsForVisualStudio2022.installer.yaml
Manifest Error: Schema Error. [Schema validation failed.
Error context: <root>[PackageIdentifier] Description: Failed to match regex specified by 'pattern' constraint.
Error context: <root> Description: Failed to validate against schema associated with property name 'PackageIdentifier'.
] File: Microsoft.RemoteToolsForVisualStudio2022.locale.en-US.yaml
Manifest Error: Schema Error. [Schema validation failed.
Error context: <root>[PackageIdentifier] Description: Failed to match regex specified by 'pattern' constraint.
Error context: <root> Description: Failed to validate against schema associated with property name 'PackageIdentifier'.
] File: Microsoft.RemoteToolsForVisualStudio2022.yaml

That doesn't really give any indication on what the issue is with the PackageIdentifier to the user - they have to manually go to the correct manifest schema and see what 'pattern' corresponds to, as well as having to interpret the long regex string to determine which part did not match it. It would be nice if either the regex pattern was displayed, or a specific error was given that indicates what is exactly wrong with the PackageIdentifier.

Proposed technical implementation details

Either one of these would be better:

• Display the regex pattern in the error message
• Detect which part failed the regex pattern and give an appropriate error message to the user. Some examples:
  • "ThisIsAPackageIdentifier" --> "PackageIdentifier must be of the form publisher.packagename"
  • "Publisher.Package?" --> "Invalid character '?' found in PackageIdentifier"
  • "123456789012345678901234567890123.Package" --> "Publisher name must be between 1 and 32 characters."
  • "1.2.3.4.5.6.7.8.9" --> "Too many parts, PackageIdentifier must be of the form publisher.packagename"

Start with the winget validate command and the PackageIdentifier schema-validation path shown in the issue. Determine whether validation can expose the failing pattern or needs PackageIdentifier-specific diagnostics; done means invalid identifiers produce actionable messages for the described malformed, invalid-character, overlong, and excessive-part examples, with validation coverage added.