Squash of 2 yoda commits:
- 77262dd0 perf(malloc): throttle malloc_trim to 1 Hz in hot paths
- 1d98eee6 perf(widget): avoid VecDeque clone in segmented_button/table Model::clear
This also changes `widget::column::with_children` and
`widget::row::with_children` to take an `impl IntoIterator` instead
of a `Vec`, like the `iced` variants of these functions do.
This shouldn't be a breaking change since passing in a `Vec` will still
compile and function exactly as before.
(Using `iced::widget::Column::from_vec` or
`iced::widget::Row::from_vec` isn't possible, since the elements of the
`Vec` aren't checked, so the size of the resulting `Column` or `Row`
won't adapt to the size of its children. Perhaps a new function could
be added to mirror `iced`'s?)
