not perform SDataRow/SKVRow convert anymore, utilize boundNullLen to facilitate the memRowType predict

calculate the memRowType precisely when NonVarType exists as to minimize the memory copy and to avoid of sorting for ordered input

[TD-11891]<fix>: where condition invalid expression error msg wrongly reported as 'not support ordinary column join'

[TD-11891]<fix>: where condition invalid expression error msg wrongly reported as 'not support ordinary column join'