40k: persist list ordering, add option to hide rules

[mardanbeigi]

For 40k:

• programmatically merge datasheets that are identical on list reorder
  • introduce hash value for units and models to identify when two units are identical
• persist the user's ordering for a datasheet. Add a button to reset the ordering
  • use data attributes for tracking order, to simplify programatic access
  • introduce hash value for roster and forces to handle different rosters with the same name
• add an option to hide army rules
• fix bug with option toggle starting collapsed if user ever collapsed or expanded it