Removal of bincode

During the work for data extensibility, it was determined that removing bincode was desireable, but not necessary in the 2.0 timeframe. This ticket is to reconsider making the change.

Discussion from #4057 copied here:

1. Data migration: All at once? vs. Lazy? vs no-migration (runtime detect of legacy structs)
Let's target for Lazy - we might change the approach if there are performance issues with two databases
2. Shall we drop bincode? Or implement the above for bincode?
Drop it! We might need it for parsing the old data, unless we migrate it