Entity score filters don't seem to work

[ltbringer]

Describe the bug
DucklingPlugin doesn't apply filters on score even when set.

Expected behavior
Entities with scores lower than the threshold were not filtered.

Desktop (please complete the following information):

• OS: Ubuntu
• Python version 3.8
• Dialogy 0.6.5

Additional context
DucklingPlugin applies filters before aggregation. The filters rely on scores and these scores are generated in the aggregation step. This means score-based filtering won't be removing any entities.