Documentation differs from Implementation for /packageManifests/{id} return codes (204 or 404)

Brief description of your issue

Hi,

according to both the 1.1.0 and 1.4.0 REST API schema, the /packageManifests/{PackageIdentifier} route is only supposed to return 200, 404 or another error:

https://github.com/microsoft/winget-cli-restsource/blob/main/documentation/WinGet-1.1.0.yaml#L506-L522
https://github.com/microsoft/winget-cli-restsource/blob/main/documentation/WinGet-1.4.0.yaml#L506-L522

However, the reference implementation also explicitly tests for the undocumented 204 here:

https://github.com/microsoft/winget-cli-restsource/blob/main/src/WinGet.RestSource/Helpers/RestSourceTriggerFunctions.cs#L63

which raises the question - should a REST source return 404 like the schema suggests when a packageIdentifier is not found or should it return 204? I have noticed in testing that winget responds with a red error message when it gets a 404 (which I guess is fine / maybe intended?) but responds with a much more calm "no results found" message when it gets a 204 - so the client seems to handle the undocumented 204 more gracefully, further hinting that that's maybe the intended return code and the schema docs are wrong?

Thanks!

Read documentation/WinGet-1.1.0.yaml and documentation/WinGet-1.4.0.yaml at the packageManifests route, then compare them with the 204 handling in src/WinGet.RestSource/Helpers/RestSourceTriggerFunctions.cs. Confirm which status code is intended for a missing package and align the schema and reference implementation so their behavior and documentation agree.