Implement highlight on change when it's set for the item

[davetcc]

This task is to enable highlight on change when it's enabled for a particular item.

It will have a BtreeList that tracks by menu item id -> ticks. When the tick count is non zero the highlight will display. A task will decrement any menu items that have a non-zero count. Each item that is chosen for highlighting will have a 4-byte memory overhead.