Rustyms

* Many bug fixes
* Moved to do all calculations on `MolecularFormula` instead of `Mass` to be able to handle isotopes and isotope patterns of fragments
* Added fragmentation of modifications of unknown position
* Added enforcement of modification placement rules of Unimod

More support for more of the Pro Forma spec, notable inclusions since the previous version:
- Support for localised possible modifications `A[Phosphog1]A[g1]`
- Support for Unimod and PSI-MOD names + accession numbers
- Support for modification chaining _ info tags `A[INFO: stuff|+42.01]`

See [the doc](https://github.com/snijderlab/rustyms/blob/main/proforma_grammar.md) for a more detailed list of all supported features.

* Removed debug output
* Fixed tests
* Added helper functionality for alignments

Initial release