DEV: enforce lal waveform kwargs usage
This MR forces all of the waveform kwargs passed to the LAL CBC waveform wrappers to avoid people accidentally misspelling kwargs, e.g., waveform_approximant
->approximant
.
The change will probably break some downstream code, but I think that in the long term it will be useful.
This revealed an issue with the test suite that is resolved in !1268 (merged).
I also refactored some of the usage of these kwargs between the two main worker functions.