[dotnet] Make WebDriver.csproj file more friendly with native pack command

[nvborisenko]

Description

Now I am able to create local nuget package with dotnet pack command.

Motivation and Context

This is one step further to be more friendly for .net devs.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the contributing document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[nvborisenko]

Build is failing, but the changes are not related to it and should not break build process. Seems it was failing before, or tools were upgraded recently.

I see it is failing because nuget tool cannot find pdb files in place? Not sure. In any case at this moment we don't need symbols because symbols even are not pushed to the nuget.org

If we cannot fix it quickly, then I can propose to turn off creation of symbols: https://github.com/SeleniumHQ/selenium/blob/a04a22f4490da1b9576f251a5f16fa34e8898645/dotnet/src/support/BUILD.bazel#LL129C31-L129C31.

And return it back after @shs96c refactors the whole process of ci for .net.

[diemol]

Thank you, @nvborisenko!