Add a flag/command to open a package's manifest in GitHub for review - perhaps `winget show --online`

Similar motivation as in https://github.com/microsoft/winget-cli/issues/1458, when researching packages. Establishing trust. Etc. But instead of showing the manifest in my CLI, sometimes I want to see it online, especially if housed in source control (i.e. GitHub).

Then I can see who contributed to a given package. I can see when it was added, updated, etc. When major changes (if any happened). And why things are the way things are. Basically a way to see a manifest's history! Not just the current state as I proposed in https://github.com/microsoft/winget-cli/issues/1458

For this, it would rock to have a command or flag to open the manifest in the https://github.com/microsoft/winget-pkgs repository, or otherwise depending on the source. Of course this assumes it is possible for a given source.

As an example, when installing the Sono's Controller app, I might want to link to https://github.com/microsoft/winget-pkgs/blob/master/manifests/s/Sonos/Controller/13.0.0/Sonos.Controller.yaml

Description of the new feature/enhancement

We have winget show currently. We could have winget show --online to open a browser and load the respective manifest for the package/version/etc.

Proposed technical implementation details (optional)

This could be as simple as displaying a URL in the CLI output (in one or more commands) and then I can click it to open it as most terminals can handle that behavior easily. For example, at the end of all calls to winget show and other places that seem natural (perhaps a detailed list of search results could include a link per package found).

Start by tracing the existing winget show command and how it resolves a package, version, and source. Determine how a source can identify an online manifest, then define behavior for supported and unsupported sources. Done means the command or flag opens or displays the manifest URL for the selected package/version.