Add CLI that runs SpEC ecc reduction script

[knelli2]

This CLI will manage the outer loop of eccentricity reduction. It should get the script for estimating the new input parameters from a SpEC directory that will be an input to the CLI. Then, when we actually write the estimation script in SpECTRE, we can point it to that.

This should go in the Support/Pipelines/Bbh pipeline and be handled automatically when doing a run.