✨ Use PowerShell internals for default installation location determination

[trackd]

added helper function to check powershell.config.json for PSModulePath.

it will only use that when -Destination is not present.

[JustinGrote]

Thanks! I'll try to review it when I can

[JustinGrote]

Thanks for taking the time to write the PR, and sorry for the delay.

I rewrote things to utilize the PowerShell logic of determining the module folder, so we don't have to deal with the powershell.json at all. This does use private methods but they are unlikely to change, and if they do, it will be because a new public method is available and we can test for that in a subsequent release.

I also simplified a lot of the flow, this was getting overly complicated and band-aided as I wrote it so it works on much more of an exception flow now to minimize the nesting.

Let me know what you and @Jaykul think, and try it out. Unfortunately writing tests is going to be tricky without potentially demolishing an existing config instance, perhaps I'll write them such that they'll trigger in CI only, but my manual testing shows it works fine in both CurrentUser and AllUser scenarios.