Rgrow

- Allow Python compilation without ui.
- Fix attachment order tracking.
- Fix tube canvas N/S boundaries.
- PyO3 0.21, with new Bound API.
- Fix python tests.

- Restructured API to allow separate, easier-to-use Systems and States.
- Refactored Python API.
- Using enum_dispatch rather than dynamic traits and boxes.
- Added Python plotting function.
- Improved Python typing.
- Fixed tube canvas implementation.
- Added more mutable parameters to kTAM.

- Python tests.
- Mismatch calculations for aTAM.
- Add several convenience functions to Python API.
- Improve documentation.

Version bump to fix some release automation problems.

The version number for Rust has been increased to give consistent version numbering for both Rust and Python.

- Combined the pyrgrow and rgrow repositories, to ease development and ensure version matching.
- Initial support for mid-simulation system parameter changes.
- RateStore multi-update optimizations.
- Significant refactoring of Python API, and more documentation.
- Calculation of mismatches and mismatch locations.
- Display improvements, with mismatches shown at higher display scales, and dynamic scaling.
- Parallel evolution improvements.
- Make UI no longer default for Python.

- Type improvements.
- Optimizations.
- thread_rng instead of SmallRng (easier code, no major performance change)
- Tiles as u32.
- Initial cffi interface.