recovery: Menu rewrites and cleanups

 * Introduce a menu stack for navigating sub-menus.  The menu data
   structure format is a bit messy, but necessary in order to provide
   a string list for the ui.

 * Create "advanced" sub-menu for rarely used and dangerous commands.

 * Create "factory reset" sub-menu for various reset and wipe commands.

 * Separate "wipe data" and "factory reset" items.

Change-Id: Ib9bc6967b98d022880cfe7fa8e324cd64b07d248