Calcite engine. Sorted index spool produces wrong collation

The sorted index spool does not take into account input collation directions and null ordering. When generating collation based on conditions, default direction and null ordering are used. This leads to wrong planning in case of not default null ordering (additional sort node inserted even if we iterating by index with required collation) and wrong index conditions usage in case of descending direction (upper and lower bound are inverted for DESC direction).