Add nuget restore CLI PackagesDirectory for package.config

[Jamie-Clayton]

• Add required option when restoring via package.config
• Add unit tests to ensure we include the CLI option

:sparkles: What kind of change does this PR introduce? (Bug fix, feature, docs update...)

Bug fix for nuget restore CLI.

:arrow_heading_down: What is the current behavior?

Nukeeper fails to restore nuget packages for older project types with package.config entries.

:new: What is the new behavior (if this is a feature change)?

Includes the missing nuget CLI option required for the restoring of packages.

:boom: Does this PR introduce a breaking change?

No

:bug: Recommendations for testing

Tested against 24 Azure DevOps private repositories with multiple private NuGet sources.

:memo: Links to relevant issues/docs

See - https://docs.microsoft.com/en-us/nuget/reference/cli-reference/cli-ref-restore. The resent nuget versions include the required option "-PackagesDirectory" when restoring via package.config files.

:thinking: Checklist before submitting

• [x] All projects build
• [x] Relevant documentation was updated
• [x] Unit test added

[Jamie-Clayton]

@AnthonySteele @MarcBruins @shep1987. Would you mind reviewing the following PR. I'm working through a series of legacy .net software solutions to sanity check the changes before creating the PR and working through the MAC, Linux AzDO pipeline you have configured.

[Jamie-Clayton]

Bump - Let's get this into main?

[skolima]

Thanks for your contribution, and for fixing my old wonky test with hardcoded credentials 😅