Retrieves available combos. This method can be used to get the list of all combos, or only the list of combos in the given state.
The currency symbol
Currency, i.e "BTC", "ETH", "USDC"
BTC, ETH, USDC, USDT, EURR Combo state, if not provided combos of all states are considered
Combo state: "active", "inactive"
active, inactive