add collapsible cell

[ftomassetti]

const collapsibleCell = (node: ModelNode, headerCell: VNode, contentCell: VNode): VNode => {
  return h('div.collapsibleCell', {}, [
    h('div.header', {}, [
      row(
        h(
          'button',
          {
            on: {
              click: (evt) => {
                console.log('click', evt.target);
                const content = $(evt.target).closest('.header').siblings('.content');
                if ($(evt.target).text() == '+') {
                  $(evt.target).text('-');
                  content.removeClass('hidden');
                } else {
                  $(evt.target).text('+');
                  content.addClass('hidden');
                }
              },
            },
          },
          ['+'],
        ),
        headerCell,
      ),
    ]),
    h('div.content.hidden', {}, [contentCell]),
  ]);
};