Additional configuration options for MSBuild-based builds (OSOE-498)

[BenedekFarkas]

1. I've already added the solution-or-project-path parameter to the MSBuild and Test workflow (passed on directly to the MSBuild action) on the dev branch in c390a0e, but we also need:
2. Parameter not to treat to warnings as errors or to be precise, treat-warnings-as-errors, but default value is true.
3. Not really a configuration option (could be, but it doesn't really matter/help), but a NuGet restore should also run explicitly before the build, because some of our solutions require that.

Jira issue