[Feature] Export metrics in OpenMetrics text format

[kaushikmadhu]

Purpose of this pull request

Implemented observability feature by exporting seatunnel-web metrics in openMetrics text standard. This will help us to raise necessary alerts in cases of resource utilization exceeding thresholds, test connection failures, or unavailability issues.
OpenMetrics format can integrate seamlessly with monitoring tools like grafana and prometheus.

Issue: apache/seatunnel#9191

Check list

• Code changed are covered with tests, or it does not need tests for reason:
• If any new Jar binary package adding in your PR, please add License Notice according
  New License Guide
• If necessary, please update the documentation to describe the new feature. https://github.com/apache/seatunnel/tree/dev/docs

[shashwatsai]

Can we please approve the workflow runs.
CC: @corgy-w , @Hisoka-X , @arshadmohammad

[shashwatsai]

@kaushikmadhu, please add the missing license headers, fix the codestyles.

[kaushikmadhu]

Formatting is fixed and license headers added to new files. Please approve the workflow runs.

[shashwatsai]

@arshadmohammad can you please re-approve the workflows?

[arshadmohammad]

Nowadays, workflows are executed without requiring approval. It seems that the CI process has already been completed, and some failures have been detected.