Allow disabling installing dependencies on restore

[tete1030]

NugetForUnity is constantly adding and installing a package, which was explicitly deleted from packages.config, when opening Unity Editor after initial clone. This package (System.Threading.Tasks.Extensions) is a dependency of another. It has duplicated definition of ValueTask class with netstandard. Deleting the package is thus necessary and has not caused any issue for me, so I have adopted this solution.

I think respecting instead of updating packages.config when restoring is a reasonable case. For this reason I added an option Lock packages on restore to disable installing dependencies of a restoring package.

I also added a timeout option for nuget mirror requests. We have used customized nuget proxy with longer http request than usual (almost 20s).

Result:

[JoC0de]

Hi @tete1030 thanks for your contribution.
Can you please describe your issue with System.Threading.Tasks.Extensions as the option Lock packages on restore is only a workaround. Normally packages that are 'not required' should be handled by UnityPreImportedLibraryResolver so NuGetForUnity doesn't even try to install them. Do you have a example NuGet package that produces the error? What version of Unity do you use? What is your target framework (Api Compatibility Level)?

[tete1030]

I agree that it's a workaround for the System.Threading.Tasks.Extensions issue alone. But for this option itself it provides more. For example it creates stable and reproducible environments and same env with CLI restoring process.

You can try the fo-dicom 5.0.3 package. We are using Unity 2022.2.2f1 and the API compatibility level is .net standard 2.1.

To reproduce, first add some script with ValueTask class. The problem cannot be seen from Unity. It compiles well without any error. However when we open the project with VS2019 or VS2022 and try to attach to unity, the error appears in VS.

[tete1030]

Do you need further information on this problem?

[JoC0de]

I just was busy. So here my review. It would be nice if you also add the new feature to the documentation (Readme.md).

[tete1030]

Thanks for your review. I will update these and the doc. Regarding TimeSpan I have a small question to discuss. Please see the comment I replied

[RoyconSkylands]

Can I bump this?
I'm running into the same issue where a dependant package keeps comming back after I delete it and remove the packages.config reference

[JoC0de]

@ConroyG OK so there is more demand. I will try to fix the last small thinks and merge the feature on the weekend.

[tete1030]

Sorry that I forgot to follow through this PR. Really appreciate the merge.