[configure args] add a way to paste/enter the whole line instead of every arg separately

### Brief Issue Summary

When I need to add lots of arguments to cmake configure, it is time consuming to do that one argument by one.

I would like to paste the whole line into the configure args field.

The issue names the CMake configure args field but no source file, entry point, or test. Start by locating that field in the extension and tracing how its input is parsed into configure arguments. Done means a user can paste a whole configure-args line and have the arguments interpreted correctly; add or run relevant tests if the existing project structure identifies them.

Written by the indexing model from the issue text.