Fix sorter

[noellehmcheng]

No description provided.

[noellehmcheng]

• remove duplicate unit names when building unit parameter that gets pass to sort function

[noellehmcheng]

#26
This pr address a circular dependency:

1. Sorter: produces stratigraphic column, but requires contacts
2. BasalContacts: produces contacts, but requires stratigraphic column
3. Contacts: needed by sorter to produce stratigraphic column

#27
This pr separates contact and basal contact extractors, but QGIS crashes when running these algorithms in sequence due to a PROJ error: osgeo::proj::io::DatabaseContext::Private::open
This pr is NOT for merging, just for testing purposes.

#28
This PR implements a custom dockwidget with separate contact and basal contact extractor algorithms that run successfully without crashes.