Modal component is an hybrid solution between :
- Vue3 modal implementation
=> with 'v-if:showModal' directive:parameter, html scope is added/removed not just shown/hidden
=> with slot we can pass content from parent component
=> some classes are passed from parent component
- Bootstrap 4.4 _modal.scss module
=> using bootstrap css classes, the modal have a responsive behaviour,
=> modal design can be configured using css classes (size, scroll)
See
* https://v3.vuejs.org/examples/modal.html#modal-component
* https://github.com/bootstrap-vue/bootstrap-vue/issues/5196
