Provide access to the axios instance

[d0rich]

Motivation: TON endpoints are really unstable sometimes and often respond with 5xx HTTP error, we need access to the axios instance making all the request in order to apply general error processing logic to it.

Example of the solution requiring an axios instance: https://www.npmjs.com/package/axios-retry