refactor: central-settlement cgs handler unit tests assertion framework to jest

[vgenev]

Goal:

As a OSS code contributor

I want to refactor the central-settlement tests

so that the narrow integration tests uses the jest native assertion framework

Acceptance Criteria:

• cgs handler tests are using jest as only test and assertion framework

Complexity:

Uncertainty:

---

Tasks:

• TBD [ @? ]

Done

• Acceptance Criteria pass
• Designs are up-to date
• Unit Tests pass
• Integration Tests pass
• Code Style & Coverage meets standards
• Changes made to config (default.json) are broadcast to team and follow-up tasks added to update helm charts and other deployment config.
• TBD

Pull Requests:

• TBD

Follow-up:

• N/A

Dependencies:

• N/A

Accountability:

• Owner: TBC
• QA/Review: TBC