ligo/lw/lsctables: add new table to store candidate parameters of each event

For GstLAL, there are often several (order 10s) candidates associated with each real gravitational wave event. These are associated with unique templates in different SVD bins all ringing up a trigger for the same event. Since we pre-aggregate these candidates before uploading them to GraceDB the candidate information for all but the max SNR or min FAR candidate is lost. However, this information can be useful namely for rapid parameter estimation techniques where it is desirable to know the template parameters of several candidates in order to determine where to lay down an initial grid in parameter space.

This MR adds a new custom table called CandidateParams which would store the component masses, z-component spins, SNRs, likelihoods, and template IDs for each candidate associated with a real event. This table would be used by GstLAL to add information for each candidate to the coinc.xml file of the favored candidate before upload to GraceDB.