Replace SBEReader

[Klankers]

The SBEReader is old, takes ages, and isn't implemented as well as it could be.

• [ ] Implement new reader for comparison to the old one during ARC01
• [ ] Add R2R style checks to assess SBE raw files for various bad things, like non-real lat/lon or line errors

It should act as a springboard to overhauling CTDCAL to use Numpy and Xarray throughout for additional speed

Some desired changes and features identified from TODOs in ctdcal are listed below, so that the TODOs can be pruned.

• Eliminate the Seabird sensor lookup table, or if not possible, consider whether it should be relocated in another module.
• Add/improve error handling.
• Add ability to substitute secondary channel for processing and derived variables.