TP2000-1651 Fix sorting on list views

[dalecannon]

TP2000-1651 Fix sorting on list views and tweak UI

Why

Filtered results on the list views are cleared if a user tries to sort a column in ascending or descending order.

What

Sorting and filtering

• Adds common utility function to return the resolved URL of the current request
• Adds capability to SortingMixin to build sorting URLs for use with create_sortable_anchor while preserving other query params such as those used for filtering
• Updates usage of create_sortable_anchor in line with the changes to SortingMixin

Other changes that have become less relevant given the upcoming redesign:

List and detail views

• Truncates long descriptions on list views
• Removes current workbasket breadcrumb
• Uses “-” in place of “None” when dereferencing null categories

Task detail view

• Adds a title caption to Indicate if task is a subtask
• Displays the parent task of a subtask

Task template detail and create views

• Adds a ‘Return to workflow template’ button

Screenshots

Detail view of a subtask

Return to workflow template button

Checklist

• Requires migrations? No
• Requires dependency updates? No