Create a base for the Clans stall

[BillTheBeast]

• Create a base prefab for the clans fown stall.
  • Current layout design here: https://docs.google.com/presentation/d/19do1K6SviYVTXB6ZBtLc_scAx4OiWbWdViIK3nbK3W4/edit#slide=id.g2bca3ad04a9_0_0
• This window should be accessible from the storage via tabline (ie. it is another window in storage) and the fleamarket (First slot in fleamarket is reserved for clans own stall).
• Add the adverticement to the left side of the screen
  • Pressing it should take the player to the editor. mainoksen muokkaus #119
  • Differing from the layout design, I would give a little more space for the adverticement. (Ie. The furniture slots aren't under it but to the right side of it.)
• Reserve space for the furniture slots.
  • Should contain a scroll rect structure with a flexible grid layout inside the content.
  • Slots aren't technically necessary yet, but I know Helena will complain if they aren't showing.
• Reserve space for the sellable furniture tray on the bottom.