test(core): long running operations tests

[Sotatek-TungNguyen2a]

Description

Add test coverage for the long running operations in the signify notification service

Checklist before requesting a review

Issue ticket number and link

• This PR has a valid ticket number or issue: link

Testing & Validation

• This PR has been tested/validated in IOS, Android and browser.
• The code has been tested locally with test coverage match expectations.
• Added new Unit/Component testing (if relevant).

Security

• No secrets are being committed (i.e. credentials, PII)
• This PR does not have any significant security implications

Code Review

• There is no unused functionality or blocks of commented out code (otherwise, please explain below)
• In addition to this PR, all relevant documentation (e.g. Confluence) and architecture diagrams (e.g. Miro) were updated

[github-actions]

Vercel PR (merge commit) deploy URL: https://cf-identity-wallet-4n7wp5ged.vercel.app

[github-actions]

Vercel PR (merge commit) deploy URL: https://cf-identity-wallet-17buq2exe.vercel.app

[github-actions]

Vercel PR (merge commit) deploy URL: https://cf-identity-wallet-4od425yft.vercel.app