fix: interface export method

[emi-tangany]

Description

Seems like the connectAsync function allows undefined and null parameter besides it also returns the Connection Object. Please if you find this PR useful feel free to merge it.

Checklist

• Format code according to the existing code style (run npm run lint:check -- CHANGED_FILES and fix problems in changed code)
• Create tests which fail without the change (if possible)
• Make all tests (unit and integration) pass (npm run test:unit and npm run test:integration)
• Extend the types in index.d.ts file (if necessary)
• Extend the README / documentation and ensure is properly displayed (if necessary)
• Provide JIRA issue id (if possible) or GitHub issue id in commit message

[github-actions]

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[emi-tangany]

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