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>

communications/slack/slack_test.go

@@ -281,7 +281,7 @@ func TestHandleReconnectResponse(t *testing.T) {
 	}
 
 	data, err := json.Marshal(testURL)
-	require.NoError(t, err, "json.Marshal must not error")
+	require.NoError(t, err, "Marshal must not error")
 
 	err = s.handleReconnectResponse(data)
 	require.NoError(t, err, "handleReconnectResponse must not error")