fix: SUBSTRING() on array typed VARCHARs throw "function substr(...) does not exist"

Refs #272

Author: ansgarbecker

source/dbconnection.pas

@@ -10958,8 +10958,8 @@ function TTableColumn.CastAsText: String;
         Result := 'CAST('+Result+' AS NVARCHAR('+IntToStr(GRIDMAXDATA)+'))';
     end;
     ngPgSQL: begin
-      if (DataType.Index in [dbdtUnknown, dbdtJson]) or (DataType.Category = dtcBinary) then
-        Result := Result + '::text';
+      // Cast *any* datatype, including VARCHAR and TEXT, which may have an [] array attribute
+      Result := Result + '::text';
     end;
   end;
 end;