Add ability to transpose Unalign<Cell<T>> and Cell<Unalign<T>> #211
Description
Add methods with signatures roughly like the following (names to be bikeshedded):
impl<T> Unalign<Cell<T>> {
pub const fn transpose_cell(self) -> Cell<Unalign<T>> { ... }
pub const fn as_transposed_cell(&self) -> &Cell<Unalign<T>> { ... }
pub const fn as_transposed_cell_mut(&mut self) -> &mut Cell<Unalign<T>> { .. }
}Note that this might also be handled if we implement generic transposition in #196.