Reorganize menu structure

This is something I've been meaning to do for a while... The menu hierarchy of farmOS is not exactly intuitive. I'd like to re-organize it around some of the basic data types: Areas, Assets, and Logs. Those should be the top-level main menu items, and they should be dropdowns that allow quick access to the sub-types.

Current structure:

  /farm

    /farm/activities
    /farm/movements
    /farm/observations
    /farm/logs

    /farm/areas
      /farm/areas/soil-tests

    /farm/plantings
      /farm/plantings/crops
      /farm/plantings/harvests
      /farm/plantings/inputs
      /farm/plantings/seedings
      /farm/plantings/transplantings

    /farm/animals
      /farm/animals/types
      /farm/animals/groups
      /farm/animals/eggs

    /farm/equipment
      /farm/equipment/maintenence

    /farm/maple
      /farm/maple/taps
      /farm/maple/sap

    /farm/substrates
      /farm/substrates/mushroom-species
      /farm/substrates/substrate-types

    /farm/sensors

Proposed structure:

  /farm

    /farm/areas

    /farm/assets
      /farm/assets/plantings
        /farm/assets/plantings/varieties
      /farm/assets/animals
        /farm/assets/animals/groups
        /farm/assets/animals/types
      /farm/assets/equipment
        /farm/assets/equipment/types
      /farm/assets/mushrooms
        /farm/assets/mushrooms/species
        /farm/assets/mushrooms/substrate-types
      /farm/assets/maple
      /farm/assets/sensors

    /farm/logs
      /farm/logs/activities
      /farm/logs/harvests
      /farm/logs/inputs
      /farm/logs/eggs
      /farm/logs/maintenence
      /farm/logs/maple-taps
      /farm/logs/movements
      /farm/logs/soil-tests
      /farm/logs/observations