[chronik-client] Enforce header with eslint plugin
Summary:
This lib should have standard headers
Add eslint plugin. For files that have not been updated since 2023, use 2023. For files new in 2024, use 2024.
Test Plan: Confirm linter change and headers look ok.
Reviewers: #bitcoin_abc, Fabien
Reviewed By: #bitcoin_abc, Fabien
Subscribers: tobias_ruck
Differential Revision: https://reviews.bitcoinabc.org/D15481