'Cycle Items', but with the ability to paste row 0 and cancel

I'm working on a modification to the [Cycle Items](https://github.com/hluk/copyq-commands/blob/master/Global/cycle-items.ini) command.

Currently the behaviour of Cycle Items is:

- Focus the window on first keypress
- Cycle to the next rows on subsequent keypresses
- Paste on key release release, but _only if the user has moved the row at least one time_. If the key is released when no subsequent keypresses have been processed, the window stays focused and nothing is pasted.

I made a modification to Cycle Items so that the first row is pasted even if the user hasn't made any subsequent keypresses. But there's an issue, I have no way to 'cancel' pasting if I change my mind after focusing the window. I'm looking for a way to listen for a particular keypress that blocks any paste from happening, whether the selected row has changed or not.

My current implementation is below. I also have an equivalent `Cycle Items Backward` command that uses `const row = rows.length > 0 ? (rows[0] - 1) % length() : 0;` instead.

```
[Command]
Command="
copyq:
// Pops up the main window (if the shortcut is pressed once), cycles through items
// (if the shortcut is pressed again) and pastes selected item when the shortcut
// is released.
const selectedRowOption = 'cycleItemsSelectedRow';
const selectedTabOption = 'cycleItemsSelectedTab';

if (focused()) {
// When the window is focused, the command should cycle through the rows
const sel = ItemSelection().current();
const rows = sel.rows();
const row = rows.length > 0 ? (rows[0] + 1) % length() : 0;
settings(selectedRowOption, row);
settings(selectedTabOption, selectedTab());
selectItems(row);
} else {
// If the window isn't open, default to selecting the first row
settings(selectedRowOption, 0);
selectItems(0);
show();

// Then wait at most 20 milliseconds for key release
while (queryKeyboardModifiers().length > 0) {
sleep(20);
}

const row = settings(selectedRowOption)
settings(selectedRowOption, row);
settings(selectedTabOption, selectedTab());
selectItems(row);

tab(settings(selectedTabOption));
select(row);
hide();
paste();
}"
GlobalShortcut="ctrl+alt+y"
Icon=\xf1b8
InMenu=true
IsGlobalShortcut=true
Name=Cycle Items Forward
```