support for calls on the marketplace

[ecbtln]

1. place an order
2. view matched orders / open orders
3. for matched orders that need btc pay, present this interface

will be able to cancel any orders listed as open

will work between any two assets

[ecbtln]

Use this API calls to get orders

also show a checkbox to filter whether or not to show expired, but default to false in UI

get_orders(filters={'field': 'address', 'op': '==', 'value': BTC_ADDRESS}})

then show order matches (only of specific addresses)

get_order_matches(filters={'field': 'address', 'op': '==', 'value': BTC_ADDRESS}, is_mine=True)

[ecbtln]

for the order matches, we only care about those that require BTCPay (one of the assets is BTC). We'll then separate the ones that we are awaiting payment for with the ones where we only have a certain amount of time to pay

[ecbtln]

b337845 fixes this