Add suggestion scoped slot

[Owumaro]

#5

• replaced the v-html on the list-item components with a prop, to be able to pass it to the scoped slot
• added a data prop on the list-item component for the scoped slot too
• added the scoped slot pass down on the main component + list component, however it's not perfect (see code comment)
  It would be way easier with this vuejs PR: feat(core): support passing down scopedSlots with v-bind vuejs/vue#7765
  Instead I had to do it manually, and met another issue (see Scoped slot always present in $scopedSlots even when v-if'd away vuejs/vue#8305 (comment))
• added an example in the demo

[alexurquhart]

Good work!