Summary:
this adds `oss-openr-linux-getdeps` to diffs affecting files under openr. With soma going away and the old fbcode_builder job disabled, this will give us the signal we need to keep the cmake build healthy.

[Some Info on Getdeps](https://our.intern.facebook.com/intern/wiki/Test_your_Open_Source_build_with_getdeps.py/)

Michael, this change may require you to bump up some of the dependent libraries and build them with cmake if not already. The main changes to the cmake script are around using package configs instead of `find_library`

Also, for those with more CMake experience: since there are some big changes in the `CmakeLists`, feel free to pour on more suggestions on how I could make it better and more aligned with other facebook OSS

Reviewed By: saifhhasan

Differential Revision: D16010068

fbshipit-source-id: 66f914f1971f826e0868c4130839380639a7e44b