Table aggregation|concatenation separator.

Possibility to add the separator for aggregation type -> group concatenation. It could be ,.;[]#XX!, etc. Currently, the separator by default is coma ",". Sometimes we need to do a step after where we split things in columns based on the separator and sometimes " , " can appear as a part of the element name which then causes the issue iF we put for example ! or $ it is less likely to appear in the element name.