Sofia

Explicit attribute conversion

Changes
- Requested entities and provided resources are now just entities. Definition syntax remains the same.
- Attribute conversions are now explicit steps.

Bug fixes
- Fixed entity caching bug where entities weren't cached between rows
- Fixed genomic feature bug where chromosome changes weren't reflected in children

Changed the way provided resources are defined to match publication documentation.
Better reporting of workflow resolution errors.

Included a toy example for users to familiarise themselves with the framework.

Fixed errors in coding sequence and position calculation

Fixed broken dependencies