[#5049] Add view option to item context menus.

[Fyorl]

• Closes Add the option to open an item in Play mode via the context menu as well as Edit #5049
• 'View' option for item context menus is now always visible, instead of only visible when the user lacks ownership, allowing users to opt-into exactly which mode they intend when opening the item sheet.
• Creating a new item now renders the sheet in Edit mode.
• Opening items from the sidebar or compendium packs will default to Edit mode, but will remember the chosen mode for the session.