[chronik-client] Add docker images required for ci deployments

Summary: Add Dockerfile for automated deployments. chronik-client should match the deployment we have setup for ecashaddrjs, as it also has npm run build as a prepublish command.

Test Plan: docker build -t chronik_client_local .

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D15051