refactor to replace docker version of yaci-cli with npm version of yaci-cli

## Refactor: Replace Docker-based integration tests with `yaci-devkit` (npm)

### Summary

Currently the integration tests in **cardano-rosetta-java** rely on a Docker-based setup to run a local Cardano devnet.
This setup should be refactored to use the **npm distribution of `yaci-cli` / `yaci-devkit`** instead.

Example reference implementation:
https://github.com/bloxbean/devkit-npm-ci-test

### Motivation

The current Docker-based approach introduces unnecessary complexity and overhead for running integration tests.

Using the npm-based `yaci-devkit` provides several advantages:

- **Simpler setup** — no Docker dependency required
- **Faster startup time**
- **More lightweight CI execution**
- **Easier local developer experience**
- **Better alignment with other projects already using npm-based devnet tooling**

### Proposed Changes

- Remove Docker-based devnet setup used in integration tests
- Use **`yaci-cli` / `yaci-devkit` via npm** to start and manage the devnet
- Update CI workflow to install and run `yaci-devkit`
- Update documentation for running integration tests locally

### Reference

Example project demonstrating npm-based CI setup:

https://github.com/bloxbean/devkit-npm-ci-test

### Expected Outcome

Integration tests should:

- Start a local Cardano devnet using **`yaci-devkit`**
- Run Rosetta integration tests against the devnet
- Shut down the devnet automatically after tests complete

The new setup should be **simpler, faster, and easier to maintain** than the current Docker-based approach.