Mexc fetchClosedOrders, fetchCanceledOrders
Mexc fetchClosedOrders, fetchCanceledOrders

Added swap functionality to fetchClosedOrders and fetchCanceledOrders:

fetchClosedOrders:
```
mexc.fetchClosedOrders (BTC/USDT:USDT)
2022-04-08T22:53:57.632Z iteration 0 passed in 282 ms

     id |      clientOrderId |     timestamp |                 datetime | lastTradeTimestamp | status |        symbol | type
| timeInForce |      side |   price | stopPrice | average | amount |    cost | filled | remaining | fee | trades | fees
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
orderId | 267544615924620800 | 1649458007000 | 2022-04-08T22:46:47.000Z |      1649458007000 | closed | BTC/USDT:USDT |
|             | open long | 42381.5 |           | 42381.5 |      1 | 42381.5 |      1 |         0 |     |     [] |   []
orderId | 267545136307721218 | 1649458131000 | 2022-04-08T22:48:51.000Z |      1649458131000 | closed | BTC/USDT:USDT |
|             |           | 42422.5 |           | 42429.5 |      1 | 42429.5 |      1 |         0 |     |     [] |   []
2 objects
```

fetchCanceledOrders:
```
mexc.fetchCanceledOrders (BTC/USDT:USDT)
2022-04-08T22:53:47.855Z iteration 0 passed in 301 ms

     id |      clientOrderId |     timestamp |                 datetime | lastTradeTimestamp |   status |        symbol | type | timeInForce |      side | price | stopPrice | average | amount | cost | filled | remaining | fee | trades | fees
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
orderId | 257198209703695360 | 1646991232000 | 2022-03-11T09:33:52.000Z |      1646991265000 | canceled | BTC/USDT:USDT |
  |             | open long | 30000 |           |         |    101 |    0 |      0 |       101 |     |     [] |   []
orderId | 259208506647860224 | 1647470524000 | 2022-03-16T22:42:04.000Z |      1647470540000 | canceled | BTC/USDT:USDT |
  |             | open long | 30000 |           |         |     10 |    0 |      0 |        10 |     |     [] |   []
orderId | 259209300336008704 | 1647470713000 | 2022-03-16T22:45:13.000Z |      1647470716000 | canceled | BTC/USDT:USDT |
  |             | open long | 30000 |           |         |     10 |    0 |      0 |        10 |     |     [] |   []
orderId | 266578267438402048 | 1649227612000 | 2022-04-06T06:46:52.000Z |      1649228942000 | canceled | BTC/USDT:USDT |
  |             | open long | 30000 |           |         |     11 |    0 |      0 |        11 |     |     [] |   []
orderId | 266585628878134784 | 1649229367000 | 2022-04-06T07:16:07.000Z |      1649230550000 | canceled | BTC/USDT:USDT |
  |             | open long | 30000 |           |         |     11 |    0 |      0 |        11 |     |     [] |   []
orderId | 266949776505921026 | 1649316186000 | 2022-04-07T07:23:06.000Z |      1649316332000 | canceled | BTC/USDT:USDT |
  |             | open long | 43541 |           |         |      1 |    0 |      0 |         1 |     |     [] |   []
orderId | 267246539385162240 | 1649386940000 | 2022-04-08T03:02:20.000Z |      1649386964000 | canceled | BTC/USDT:USDT |
  |             | open long | 30000 |           |         |      2 |    0 |      0 |         2 |     |     [] |   []
orderId | 267246878490446336 | 1649387021000 | 2022-04-08T03:03:41.000Z |      1649387126000 | canceled | BTC/USDT:USDT |
  |             | open long | 30000 |           |         |      2 |    0 |      0 |         2 |     |     [] |   []
orderId | 267536827764787712 | 1649456150000 | 2022-04-08T22:15:50.000Z |      1649456156000 | canceled | BTC/USDT:USDT |
  |             | open long | 29000 |           |         |      7 |    0 |      0 |         7 |     |     [] |   []
orderId | 267544301649613824 | 1649457932000 | 2022-04-08T22:45:32.000Z |      1649457996000 | canceled | BTC/USDT:USDT |
  |             | open long | 23000 |           |         |      9 |    0 |      0 |         9 |     |     [] |   []
orderId | 267545611165848576 | 1649458244000 | 2022-04-08T22:50:44.000Z |      1649458265000 | canceled | BTC/USDT:USDT |
  |             | open long | 12345 |           |         |     73 |    0 |      0 |        73 |     |     [] |   []
11 objects
```

ccxt/ccxt,ccxt/ccxt,ccxt/ccxt,ccxt/ccxt,ccxt/ccxt