Replace c++/cli wrapper by c# wrapper

[robdeltares]

Kind of request

None

Enhancement description

The new C# wrapper should use the CWrapper to access all underlying functionality

Use case

No response

Additional context

No response

[robdeltares]

PR: #305 and https://github.com/Deltares/PTK/pull/88

[epsig]

Besides some remarks on the actual implementation, I have a few remarks:

• there is no (internal) documentation of the new C# code
  at least should be documented how the callback works, and why an earlier attempt did not work well
• the cli code should be removed now
• by opening the solution, Visual Studio gives an error
• the python tests are gone in the test explorer
• I expected the c-sharp projects to be any cpu
• the c-sharp is not part of the cmake build ; that is needed to make it visible in Sonar Cloud, but there may be more needed to get it working in the Sonar upload.

[robdeltares]

Some more needs to be done to complete this issue:

• Update tests for upscaling / length effect (PTK 86)
• Remove proxies based in u-values and all variables (PTK 87)
• Make build server more robust