swri_transform_util: try to find PROJ with CMake
swri_transform_util: try to find PROJ with CMake

PROJ provides CMake config files when installed with CMake (rather than
autotools, as is done in Debian/Ubuntu). Versions older then 8 (which
isn't compatible with swri_transform_util) don't install a pkg-config file
when installed with CMake. Therefore, the build currently fails to find
PROJ on systems where it is not installed to /usr.

This patch causes all three methods to be tried in sequence, so should be
compatible with all these possibilities. I don't see why using
find_library() would ever be necessary, but I kept it to maintain
compatibility.

swri-robotics/marti_common,swri-robotics/marti_common,swri-robotics/marti_common,swri-robotics/marti_common