Call size_hint from Map

[tarkah]

Default size_hint implementation calls size. This is an issue with the following view, where component is a lazy::Component:

column![
  component.map(..),
]

This resolves to Column::push calling Map::size_hint which calls Component::size during view, and causes a panic because the components internal option state hasn't been set yet, which happens during Widget::state / diff.

[hecrj]

Good catch!

I think Explain in the core::element module may have the same issue.