If the PYSON statement has the type 'object', it can be a Date, DateTime or
TimeDelta which is allowed for comparison.
Closes#13645
(grafted from df6e3c10a5105e545e1aa8e58c3c087285146a58)
--HG--
branch : 6.0
This is needed to keep the empty string in the list on a second parsing.
Closes#13558
(grafted from 747825bc93a35fef995094be5ca9d7e04c414692)
--HG--
branch : 6.0
The left part must be returned because when the value is unique we also use the
name of field for further checks
Closes#11952
(grafted from 5ae26db33565f1d67e5eb2ae975f5c16a38cd4d9)
--HG--
branch : 6.0