Remove src/test/* from type definitions file

[thompsongl]

Summary

Closes #3709 by removing src/test/* files from eui.d.ts. Additionally generates new lib/test/index.d.ts and es/test/index.d.ts files specifically for consumers who use test directory utilities.

As src/test is not formally part of EUI's API, test imports occur from lib or es and are @ts-ignoreed. This PR is an enhancement for those imports, as types will automatically be picked up when importing from @elastic/eui/[lib, es]/test.

Removing src/test from eui.d.ts allows for @types/enzyme to be moved back to devDep status. Use of lib/test or es/test assumes your project maintains its own @types/enzyme dependency

Checklist

- [ ] Check against all themes for compatibility in both light and dark modes
- [ ] Checked in mobile
- [ ] Checked in IE11 and Firefox
- [ ] Props have proper autodocs
- [ ] Added documentation
- [ ] Checked Code Sandbox works for the any docs examples
- [ ] Added or updated jest tests

• Checked for breaking changes and labeled appropriately

- [ ] Checked for accessibility including keyboard-only and screenreader modes

• A changelog entry exists and is marked appropriately

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_3715/

[chandlerprall]

• We should probably do the same for es/test
• Instead of placing the new .d.ts in the top-level and requiring the project to add a configuration, it looks like we can put index.d.ts files in the lib/test&es/test dirs and typescript will automatically pick them up when importing that directory. This wouldn't allow imports from deeper directories, but we don't support that as a pattern from the lib/es directories either - i.e. everything has to start at the @elastic/eui entry.

[thompsongl]

put index.d.ts files in the lib/test&es/test dirs and typescript will automatically pick them up

Yep, this is a better approach. Tested in Kibana without altering tsconfig.

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_3715/

[chandlerprall]

The generated files don't look correct, all of the declare module statements define @elastic/eui/lib/test but that makes the index.ts definition re-export from the non-existent definitions

declare module '@elastic/eui/lib/test' {
	export { requiredProps } from '@elastic/eui/lib/test/required_props';
	export { takeMountedSnapshot } from '@elastic/eui/lib/test/take_mounted_snapshot';
	export { findTestSubject } from '@elastic/eui/lib/test/find_test_subject';
	export { startThrowingReactWarnings, stopThrowingReactWarnings, } from '@elastic/eui/lib/test/react_warnings';
	export { sleep } from '@elastic/eui/lib/test/sleep';

}

[thompsongl]

The generated files don't look correct

Good catch. Updated to include full module names.

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_3715/

[chandlerprall]

Changes LGTM! Ran build locally, confirmed enzyme and the test utilities are no longer mentioned in eui.d.ts and are now present in es/index.d.ts and lib/index.d.ts

[thompsongl]

jenkins test this

"PUPPETEER_SKIP_CHROMIUM_DOWNLOAD"

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_3715/