`TagHelperDescriptor.GetAllDiagnostics()` does not include diagnostics from `BoundAttributeParameterDescriptors`

[DustinCampbell]

It appears that it was an oversight to not include diagnostics from any BoundAttributeParameterDescriptors when calling TagHelperDescriptor.GetAllDiagnostics(). IMO, it seems a fairly safe change to make since any callers of this API would've expected that they'd receive all diagnostics.