[JS] add Vector.map

Add `Vector.map(f)` that returns a new vector transformed with `f`

**Reporter**: [Brian Hulette](https://issues.apache.org/jira/browse/ARROW-2765) / @TheNeuralBit

_{**Note**: *This issue was originally created as [ARROW-2765](https://issues.apache.org/jira/browse/ARROW-2765). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}