For the c++ api dox this expands to "\c nullptr" (the
\c directive indicates a code literal value), and for sipify/Python
it expands to ``None`` (`` is sphinx annotation for literal values)
Makes for nicer dox for both c++ and Python!
as well as just variable names
In some cases contexts may provide specific functions of use
to that context, or more generally there may be functions we want
to highlight for a particular expression builder (e.g. highlighting
to_dms in the grid annotation builder)
The value relation widget filter expression can now use two
new functions/variables that have access to the current
values and geometry of the form being edited.
This allows for dynamic filtering (drill-down) as explained
in the crowdfunding page:
https://north-road.com/drill-down-cascading-forms/
The new functions/variables are:
Function:
get_current_form_field_value( 'FIELD_NAME' )
Variable:
@current_form_geometry
