feat(bmr): Add information about relay node stats

[andrii-kl]

Overview

Implement endpoint with authentication, to provide Relay stats.

Example:

------------------------------------------------
chain 1 -> chain 288
Received 256 transfers
Successfully processed 234 transfers
Success rate: 91.40%
Token name: USDC, transfer volume:25000 USDC, earned fee:25.31 USDC
Token name: DAI, transfer volume:9800 USDC, earned fee:12.58 DAI
Balance relay wallet: 200 ICX
------------------------------------------------
chain 42161 -> chain 1
Received 1678 transfers
Successfully processed 1620 transfers
Success rate: 96.54%
Token name: USDC, transfer volume:96250 USDC, earned fee:150.96 USDC
Balance relay wallet: 20 BNB
------------------------------------------------

Story

As a [Relay owner/manager/admin], I want [to know the relay stats] so that [make relay working process transparent and traceable]

[CyrusVorwald]

This is a great idea. Is this example from another relay implementation?

[andrii-kl]

@CyrusVorwald-ICON Yes, it is from the cbridge project with small changes

[andrii-kl]

In the process of discussion: https://github.com/icon-project/icon-bridge/discussions/806