Demo: use Granite styles

[danirabbit]

Todo:

• [ ] https://github.com/elementary/granite/pull/704
• [ ] https://github.com/elementary/granite/pull/708
• [ ] https://github.com/elementary/granite/pull/712
  • [ ] spinbutton
  • [ ] .password
• [x] List
  • [ ] row.activatable
  • [x] .rich-list
• [ ] Frame
  • [ ] .frame
• [ ] .terminal
• [ ] toast
• [ ] button
  • [ ] .text-button
  • [ ] .link
  • [ ] .suggested
• [ ] .linked
• [x] popover
  • [ ] Separator
  • [ ] disabled
  • [ ] mnemonics
  • [ ] fix scrollbar padding
• [ ] Install check-checked-symbolic.svg to host
• [ ] paned
• [ ] stackswitcher
• [ ] floating headerbar style
• [ ] DatePicker
• [ ] TimePicker
• [ ] spinner not spinning?
• [ ] expander