Make Option impl more readable (use same code as for array impl)

[Boscop]

The code for Option

serde-diff/src/implementation.rs

Lines 315 to 356 in e461da4

	let mut self_iter = self.iter();
	let mut other_iter = other.iter();
	let mut idx = 0;
	let mut need_exit = false;
	let mut changed = false;
	loop {
	let self_item = self_iter.next();
	let other_item = other_iter.next();
	match (self_item, other_item) {
	(None, None) => break,
	(Some(_), None) => {
	let mut num_to_remove = 1;
	while self_iter.next().is_some() {
	num_to_remove += 1;
	}
	ctx.save_command::<()>(&DiffCommandRef::Remove(num_to_remove), true, true)?;
	changed = true;
	}
	(None, Some(other_item)) => {
	ctx.save_command::<()>(
	&DiffCommandRef::Enter(DiffPathElementValue::AddToCollection),
	false,
	true,
	)?;
	ctx.save_command(&DiffCommandRef::Value(other_item), true, true)?;
	need_exit = true;
	changed = true;
	}
	(Some(self_item), Some(other_item)) => {
	ctx.push_collection_index(idx);
	if <T as SerdeDiff>::diff(self_item, ctx, other_item)? {
	need_exit = true;
	changed = true;
	}
	ctx.pop_path_element()?;
	}
	}
	idx += 1;
	}
	if need_exit {
	ctx.save_command::<()>(&DiffCommandRef::Exit, true, false)?;
	}

would be more readable if written like the code for arrays

serde-diff/src/implementation.rs

Lines 25 to 37 in e461da4

	let mut need_exit = false;
	let mut changed = false;
	for (idx, (self_item, other_item)) in self.iter().zip(other.iter()).enumerate() {
	ctx.push_collection_index(idx);
	if <T as $crate::SerdeDiff>::diff(self_item, ctx, other_item)? {
	need_exit = true;
	changed = true;
	}
	ctx.pop_path_element()?;
	}
	if need_exit {
	ctx.save_command::<()>(&DiffCommandRef::Exit, true, false)?;
	}