Add cmake support

[fritzm]

Adds ability to build package with CMake in addition to eupspkg (allows to be included as submodule in other CMake projects, e.g. Qserv.)

[timj]

Does log really need base? If it doesn't, can you create a github action that builds this package and runs the tests with cmake? You can install utils using pip as daf_butler already does (it looks like you only use one python functions from utils). This would be great since it would allow us to run tests for every PR without relying on jenkins and make sure that no-one breaks cmake.

[fritzm]

Does log really need base?

Good question -- I didn't really re-examine the eups table files etc. in this work. I can try some experiments and see, though...

[timj]

Just try a GitHub build action using cmake and pip install of utils and see what happens. You can look at daf_butler or utils github actions for help and you will need to install some python packages (utils is a better template because it doesn't use conda and just pip installs -- daf_butler show you how to pip install utils into the action environment though).

[fritzm]

@timj Okay, took about a dozen commits to get that straight :-) Squashed and re-pushed. Give a look and see what you think?

[fritzm]

@timj Okay, GHA is running python tests against the cmake-built artifacts now. I will to similar for the sphgeom PR.

[timj]

Thanks for adding the python tests.