Filter property

## Filter property User can use **F(Filter)** property to filter data. It supports following usages: - **Conditional Filter**: Filtering data using conditional statement expressions, for example: **{{ds2.name(F=(ds2.customerID = ds1.customerID ))}}** - **Slice filter**: Filtering data using Python-like slice syntax, for example: **{{ds1.orderID(F=[0:20:2])}}**