ui: use modal menu for inventory management instead of sidebar

[skleinjung]

• Require escape key to configure after dying instead of any key.
• Add supporting for customizing item content in container contents panel.
• Navigate menus with the same keys as the map.
• Move inventory management to modal instead of sidebar.
• Show slot items are equipped in on sidebar.
• Move traversability checks out of creature and into move action.
• Remove map dependency from creatures.
• Print the items in a cell when entering it.
• Update item list visual styles to separate options from description more clearly.
• Add ability to render item description in container contents panel.
• Disable sidebar hover and click events.