test: [OS-590] update ESE controller tests to use real OSCARS logic

[haniotak]

Description

modify ESE tests to use actual OSCARS logic; re-use L2VPN JSON steps
added some JsonSetters so that we can deserialize the objects we serialize

Checklist

• PR Title format: type: [OS-XXX] Short description
  • type is one of: 'build', 'ci', 'chore', 'docs', 'feat', 'fix', 'perf', 'refactor', 'revert', 'style', 'test'
  • OS-XXX refers to a Jira issue.
  • If this is a breaking change prefix the description with "BREAKING CHANGE:"
• There is a related Jira issue for this pull request
• Description should be a meaningful summary of the changes you are proposing
• For breaking changes prefix the title with "BREAKING CHANGE:" and include details in the description
• This PR includes tests related to these changes, or existing tests provide coverage
• This PR has updated documentation as appropriate
• mvn clean package runs successfully

Notes

• Once approved, use the squash and merge option.
• Refer to the development notes for more details.