== Add TimeInterpreter, necessary queries, and a way to run them
Add tests comparing them with old implementation

== Fundamentally change wallet to use SlotNo instead of SlotId
- Patch together cardano-wallet-jormungandr to still work, despite the
binary using SlotId.

== Remove redundant byron code

== Sync progress calculation compares times now instead of slots

It would group slots like:

Epoch 1:
  SlotNo 0
  SlotNo 8
Epoch 0:
  SlotNo 11

when it zipped the grouped slots together with the epochs.

I'm not sure how it worked previously and stopped working now.

I also added a somewhat ugly shrinker for the stake pool fixtures.

We previously encoded
    SlotId = (epoch, slotInEpoch)
in the `slot` tables as a single, flat integer (using an artificial
epoch length)

We are now storing the SlotNos.

It would be VERY BAD if a new wallet would read re-interpret the old
wallet data incorrectly.

Renaming the fields should trigger the automatic DB migration.

This reverts commit 9eb843b.

That commit broke a unit test failure for a manual migration. I am not
sure if the test could have been removed without consequences.

But weirdly, migration seems to work smoothly without it:

$ cardano-wallet-shelley-2020-07-06 serve --node-socket socket --testnet shelley_testnet-genesis.json --database wallet-db
$ # Create a wallet
$ cardano-wallet-shelley transaction list <WALLET ID>

$ cardano-wallet-shelley serve --node-socket socket --testnet shelley_testnet-genesis.json --database wallet-db
$ cardano-wallet-shelley transaction list <WALLET ID>

$ # The correct slots are still shown.

Looking in the DBs, it seems like wallet does detect that the schema has
changed, and re-syncs from genesis.