[BUG] Export types for /lib/test

[ashwin-pc]

Describe the bug

In OpenSearch Dashboards we use exported test functions such as findTestSubject from oui. These however throw type errors because the type is not exposed similar to the components.

To Reproduce
Steps to reproduce the behavior:

1. Go to OpenSearch Dashboards repository
2. open the file src/plugins/dashboard/public/application/dashboard_empty_screen.test.tsx
3. see typescript error

Expected behavior
Expose the types for the test functions too

OpenSearch Version
3.0
Dashboards Version
3.0
Plugins

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Host/Environment (please complete the following information):

• OS: [e.g. iOS]
• Browser and version [e.g. 22]

Additional context

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[Nicksqain]

Is it necessary to fix the types? After all, you can update the source of the import, since a new module is declared, the reference should be
import { findTestSubject } from '@opensearch-project/oui/lib/test/find_test_subject';

[ashwin-pc]

Honestly it might just be as simple as exporting the function type thats already declared here: https://github.com/opensearch-project/oui/blob/main/src/test/find_test_subject.ts#L52-L56. But i havent looked into it yet. Thats why i'm simply calling out the symptom.

[joshuarrrr]

I have some recollection that this has been fixed...

[joshuarrrr]

Fixed via opensearch-project/OpenSearch-Dashboards#3798, I believe.