exchanges: Limit mock test JSON data size by truncating slices and maps (#1968)

* set limiter to first level mock data list and updated unit tests

* address nested slices length limit

* minor fix recording file and update unit tests

* minor updates on unit tests

* re-record mock files and minor fix on the unit tests ti adapt the mock data change

* improve http recording limit value and fix issues with mock data in binance

* added MockDataSliceLimit in request items and resolve minor unit test issues

* resolve missed conflict

* rename mock variables, resolve unit test issues, and other updates

* minor fix to CheckJSON and update unit tests

* minor unit test fix

* further optimization on mock CheckJSON method, unit tests, and re-record poloniex

* common and recording unit tests fix

* minor linter issues fix

* unit tests format fix

* fix miscellaneous error

* unit tests fix and minor docs update

* re-record and reduce mock file size

* indentation fix

* minor assertion test fix

* reverted log.Printf line in live testing

* rename variables

* update NewVCRServer unit test

* replace string comparison with *net.OpError check

* restructur net error test

* exchanges/mock: Remove redundant error assertion message in TestNewVCRServer

---------

Co-authored-by: Adrian Gallagher <adrian.gallagher@thrasher.io>

testdata/http_mock/exclusion.json

@@ -16,6 +16,7 @@
   "account_number",
   "username",
   "login",
+  "secret",
   "apiKey"
  ]
 }