This PR allows to select a region using the 'Box' or 'Lasso' tool in the scatter plot and then submit a query for the selected region. This feature is only working for a postgres database since it's using the postgres native functions/types polygon and point.
Basically, we construct a query out of the selection points

SELECT *
FROM "user_schema"."user_table" as t
WHERE POLYGON '("POLYGON POINTS")' @> POINT(t.selectedX, t.selectedY});

The features requires python3-queryparser >= 0.7.3 , see aipescience/queryparser#24

Note: The selection work purely on a flat surface using Cartesian coordinates.