exchanges: Remove FTX implementation and fix minor test issues (#1100)

* exchanges: Start removal of FTX

* Get tests happy again

* okx: improve logic and add basic coverage

* Fix linterino

* Round 2 plus rm useless assignment in test

* Fix exchange_wrapper_issues test error

* Fix nitters

* Address nitters

cmd/exchange_wrapper_issues/wrapperconfig.json

@@ -106,11 +106,6 @@
    "secret": "Secret",
    "otpSecret": "-"
   },
-  "ftx": {
-   "key": "Key",
-   "secret": "Secret",
-   "otpSecret": "-"
-  },
   "gateio": {
    "key": "Key",
    "secret": "Secret",