Changed
- Changed default `SCRATCH_DIR` from `/tmp` to `Path.cwd() / .scratch`
- Refactored decorator handling to be more concise
- Renamed `[optimizers]` extras to `[sella]`
- Moved `quacc.utils.wflows` into `quacc.wflow_tools.decorators` and `quacc.wflow_tools.prefect`
- Moved `quacc.utils.db` into `quacc.wflow_tools.db`
- Moved `quacc.utils.calc` to `quacc.runners.ase`
- Moved `quacc.presets` to `quacc.calculators.presets`
Fixed
- Fixed parsing of `RESULTS_DIR` and `SCRATCH_DIR` paths when they contain `~`
- Symlinks are no longer created if `RESULTS_DIR == SCRATCH_DIR` since this is redundant
- If `RESULTS_DIR` or `SCRATCH_DIR` are not present, they will be automatically made