JavaFX: Move src.zip out of the lib directory

In the standalone JavaFX SDK, we deliver a set of modular jars in the lib directory. We also deliver a src.zip for use by IDEs into that same directory. If you add the lib directory to your application's module path in your IDE, it will try to load src.zip as if it were a jar file, and will fail. This is a pain point for developers using the SDK.

We should move the src.zip file to a different directory. Possible options include:

1. The top level directory of the SDK
2. A new directory that would be a sibling of lib
3. A new sub-directory under lib

This will need a CSR.