Branch to build coda-oss as shared library on Windows

[mpolder]

I have a branch to build coda-oss as a shared library on Windows/Linux, tested with Visual Studio 2019 and gcc 11. The branch is at https://github.com/mpolder/coda-oss/tree/develop/build-coda-as-shared-library. I tried creating this branch as a pull request on this repository but was unable to, likely due to permission issues. I've run the unit tests and everything that passes on main passes on this branch.