Remove items code duplication between stores

[hassnian]

after #10842

we might need to reuse the same logic in future stores

I'd like a solution that has less code duplication, ideally some utils

stores: listingCart, makeOffer

pls read thread

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can we make some utils so we don't duplicate this code , and can reuse it in future stores :D

    setItem(payload: MakingOfferItem) {
         addItem(this.items, payload)
    },
    updateItem(payload: Partial<MakingOfferItem>) {
          updateItem(this.items, payload, payload.id)
    },
    removeItem(id: ID) {
      removeItem(this.items, id)
    },

Originally posted by @hassnian in #10842 (comment)