Add QEdge.qualifier_constraints and rename to attribute_constraints

[edeutsch]

No description provided.

[vdancik]

What would be a mechanism for OR and NOT queries, e.g get me all compounds that decrease activity or synthesis of gene but not its expression? Here is an example of current way of asking such questions: https://github.com/NCATSTranslator/testing/blob/main/ars-requests/not-none/stk11downregulators.json

[ehinderer]

@vdancik That query has "biolink:decreases_expression_of" in the edge predicate list, isn't the point to exclude that logic? Also some of those predicates don't seem to be in the Biolink model.

[edeutsch]

Closing because subsumed into #330