csharp: Export correct headers and files
Some headers and test files were not being exported in autotools.
Also reordered the headers for better tracking.
Test Plan: run make dist and check if resulting tarball builds with --enable-csharp-bindings
Reviewers: stefan_schmidt, zmike, bu5hm4n, segfaultxavi, cedric, devilhorns
Reviewed By: segfaultxavi
Differential Revision: https://phab.enlightenment.org/D8324