Compress-PSResource should output a FileInfo object

[sdwheeler]

Summary of the new feature / enhancement

By default, this command doesn't write any output to the pipeline. When you use the PassThru parameter, it returns full path of the .nupkg as a string. This should be a FileInfo object like most other commands return.

Proposed technical implementation details (optional)

Be sure to set the [OutputType()] attribute on the cmdlet.