On the way re-design the API by doing:
- Introduce `Checked` and `Unchecked` tags
- Rename the `txdata` field to `transactions`
- Make the `Block` fields private
- Add getters for `header` and `transactions` fields
- Move the various `compute_` methods to be free standing functions
- Make the `check_` functions private
- Introduce extension traits
the `blockdata` directory is code organisation thing, all the
types/modules are re-exported from other places. In preparation for, and
to make easier, the `primitives` crate smashing work - remove all
explicit usage of `blockdata`.
Note that the few instances remain as they seem required e.g.,
`pub(in crate::blockdata::script)`
Refactor only, no logic changes.
AFAICT we literally never used this; it was available only on the
bitcoin targets and not the honggfuzz ones; AFL has a broken dep
tree (or at least, requires some more MSRV pins that I did not care
to investigate).
Just remove it entirely.