Jack Grigg

Moving this into a separate repository.

The rationale for file-per-block was simplicity, on the basis that you shouldn't have millions of files in a single directory. You'd maybe have thousands (my Rust CLI wallet fetches batches...

Let's try changing the timeout from 5 minutes to 2 hours in the next release. We don't want to block indefinitely, but all that the timer prevents is the wallet...

[Rebased on current `master`](https://github.com/zcash/zcash/compare/7d800eb892bec90367da2362bbeda42c0bab5afb..714ac038ec96f528e51a839b20a52231736ca14e).

[Rebased on current `master`](https://github.com/zcash/zcash/compare/714ac038ec96f528e51a839b20a52231736ca14e..f0badcc987070fcd25c48ce0f69328c78f4004bf).

[Rebased on current `master`](https://github.com/zcash/zcash/compare/f0badcc987070fcd25c48ce0f69328c78f4004bf..69b21123a5ade48418c21500111a870a5f4a8f96).

[Rebased on `master`](https://github.com/zcash/zcash/compare/69b21123a5ade48418c21500111a870a5f4a8f96..2602dd874dbb331600f971a5233b59e0987b8fc4) to include recent CI fixes, and to use the Orchard batch scanning results in the wallet.

[Force-pushed](https://github.com/zcash/zcash/compare/2602dd874dbb331600f971a5233b59e0987b8fc4..104d46df33384463f7dc1523e57288938afb1f2f) to fix Clippy lints.

[Rebased on `master`](https://github.com/zcash/zcash/compare/104d46df33384463f7dc1523e57288938afb1f2f..e9df490d458ba478d9ba85170e2f2a05c6c66ff0) to bring in dependency updates and (hopefully) CI fixes.

[Rebased on `master`](https://github.com/zcash/zcash/compare/e9df490d458ba478d9ba85170e2f2a05c6c66ff0..53befdf4f6f58d20b2e13de733fbcf71e07efe9f) to bring in another CI bugfix.