[node-rewards-program] task: add service to communicate with API

[OlegMakarenko]

What was the issue?

• Node Rewards Program module doesn't have service to communicate with API.

What's the fix?

• Added Node Rewards Program service.
• Added prepareEnrollTransaction() which returns transfer transaction filled with an enrollment data.
• Added checkEnrollmentAddress() which calls /enrollment/check/address/<address_str> and maps result to boolean.
• Added checkEnrollmentStatus() which checks if a signer public key is enrolled in the current period. It fetches latest successful enrollments from /enrollment/successes/<public_key_str> and check wheter a recipient address is the current enrollment address.
• Added getEnrollmentHash() which fetches codeword dependent hash from /codeword/<public_key_str>.
• Added getNodePayouts() which fetches payout information for a single node from /node/<int:node_id>/payouts.
• Added getNodeInfo() which fetches detailed information about a single node from /node/<node_id>.

[yilmazbahadir]

I think we should also add some unit tests as well.

[yilmazbahadir]

Are the tests passing in your local?

[OlegMakarenko]

Works fine on my local.

Did you try npm run build?

[yilmazbahadir]

I think I missed it this time, looks okay 👍