`addToProject` for adaptify tool

[haraldsteinlechner]

this one adds the option to patch project files while running adaptify locally using --addToProject. The approach is as follows:

• run everything normally, but log all model and model.g files
• in a second step Microsoft.Build is used to patch the project accordingly (if needed and the .g files is not yet present)

for robustness, this is in a separate library and only referenced in the adaptify tool.

[haraldsteinlechner]

after some tweaking it seems to work just fine. We are currently in testing phase in PRo3D: https://github.com/pro3d-space/PRo3D/pull/273

EDIT: i released it as a prerelease package

[haraldsteinlechner]

i just added --hideGenFiles option which hides .g.fs files in project files using Visible="false" attributes. Unfortunately it is a bit hacky since Microsoft.Build.Construction seems not to support the attribute. Anyhow, this looks quite promising... i deployed it as 1.2.0-prerelease3