Sign transaction

curl --request POST \
  --url http://0.0.0.0:3010/sign-async \
  --header 'Content-Type: application/json' \
  --data '{
  "type": "request",
  "keyPassword": "<string>",
  "keyFilename": "<string>",
  "transactionRequestId": "<string>",
  "masterPassword": "<string>",
  "apiKey": "<string>",
  "apiSecret": "<string>",
  "signRequest": {}
}'

{
  "transactionRequestId": "<string>",
  "sessionKey": "<string>",
  "sessionTimestamp": "1608296004000"
}