Transactions Fee / Average Txn Fee metrics broken

[karinayavorska]

Describe the bug
The two dedicated statistics routes and their backup API endpoints return HTTP 404 Not Found on all SKALE Explorer networks (testnet, dev, and mainnet):

1. /stats/txnsFee
2. /stats/averageTxnFee

To Reproduce
Steps to reproduce the behavior:

1. Go to https://juicy-low-small-testnet.explorer.testnet.skalenodes.com/ or any other schain
2. Then go to Transactions
3. Click on Transactions Fee or Average Txn Fee
4. See error 404 Page not found

Expected behavior
Both routes should return HTTP 200 and display historical graphs for the selected period.

Screenshots

Desktop (please complete the following information):

• OS: Ubuntu 24.04.1 LTS
• Browser Chrome
• Version 134.0.6998.165