Simplify an Object by Two Properties

You were tasked with making a list of every makeup item your local pharmacy had in stock. You created a very long array of each item, with each element having both a name and brand property. Now you're looking to simplify the list by combining duplicate items, and adding a count property to everything.

Example

simplifyList([
  { brand: "NARS", name: "Cosmetics Voyageur Pallete" },
  { brand: "NARS", name: "Cosmetics Voyageur Pallete" },
  { brand: "Urban Decay", name: "Naked Honey Pallete" },
  { brand: "Stila", name: "Stay All Day Liquid Lipstick" },
  { brand: "Stila", name: "Stay All Day Liquid Lipstick" },
  { brand: "Stila", name: "Stay All Day Liquid Lipstick" }
]) ➞ [
  { brand: "NARS", name: "Cosmetics Voyageur Pallete", count: 2 },
  { brand: "Urban Decay", name: "Naked Honey Pallete", count: 1 },
  { brand: "Stila", name: "Stay All Day Liquid Lipstick", count: 3 }
]

Notes

• There will always be one or more element in the given array.
• Each element will always have a brand and name property.
• All duplicates will be displayed in order.