[Feature Request] Parallel Dependency installations

[kilasuit]

When installing meta modules like Az / AzureRM each of the required modules gets installed sequentially which is painfully slow and could be greatly improved.

Therefore I would ask that as a feature request for PSGet v3 that dependencies could be installed via some form of parallelisation as to reduce overall installation time

[SteveL-MSFT]

It makes sense to install in parallel and resolve dependencies so they aren't installed multiple times (like in the case of Az modules all depending on Az.Accounts).

[JustinGrote]

My recommendation would be to basically just execute a NuGet restore, it already has all the logic in there to do this in parallel and handle all the dependencies. I'll reference my Modulefast POC again https://gist.github.com/JustinGrote/ecdf96b4179da43fb017dccbd1cc56f6 which installs all the Az modules (which are a really good test case due to their metapackages and dependencies) in less than 5 seconds