Inbound Agent support

[vikrantsnirban]

Enabling Inbound Agent to avoid SSH Connectivity under controlled environment.

Testing done

Installed Plugin to Jenkins and able to create Inbound Agent on-demand by running pipeline with provided label.

Submitter checklist

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• Ensure that the pull request title represents the desired changelog entry
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• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests that demonstrate the feature works or the issue is fixed