Add VSCode launch.json config for debugging

[e1turin]

VSCode projects are ready for building and running with CLI, but there is no ready configuration for debugging from the editor. It whould be better to have such configuration for every project.

Configuration should

• be simple
• be universal for different executable targets (maintain a balance of simplicity)
• support different extension groups (ms cpptools debugger or lldb (official or from Vadim))