- write generated migration files to OUT_DIR instead of source directory
- copy migration SQL files to OUT_DIR for inclusion in build artifacts
- use absolute paths from OUT_DIR in include_str! macros
- update consumer modules to include from OUT_DIR using concat! macro
these changes enable cdk to support nix sandbox builds
* Fix migrations ordering
1. Fix postgres migration prefixes for unreleased migrations
2. Fix build script to try to sort, if provided, the filename prefix as a
number, otherwise fallback to the sorting by filename as string
* Fixed clippy issues
The primary purpose of this new crate is to have a common and shared codebase
for all SQL storage systems. It would force us to write standard SQL using best
practices for all databases.
This crate has been extracted from #878
