Fix e2e-test-utils-playwright's jsdoc and types

[kevin940726]

What and why?

This PR does two things:

1. Fix jsdoc in e2e-test-utils-playwright when using from a fixture. Now it correctly shows the jsdoc when hovering over a method.
2. Remove jsdoc types in favor of typescript types. jsdoc types are never enforced and can be out-of-sync. It's preferred to refer to the TS types if possible.

How?

Use the fancy @borrows jsdoc magic to borrow jsdoc from a pure function to a class field. Due to some circular dependencies issue, we also have to manually type the class field with : typeof methodName to show the jsdoc.

Testing Instructions

npm run build:packages

Hover over some util in the supported editors and see the jsdoc.

Note:
You have to call the function to be able to show the full jsdoc. That is, hovering over editor.getBlocks won't show the jsdoc, but hovering over editor.getBlocks() will show the jsdoc. This is probably a jsdoc or typescript bug.

Screenshots or screencast

jsdoc in VSCode:

[github-actions]

Flaky tests detected in 3dada1e345e52fcc4c522db1e77935bb8b2f0e6f.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/4229596957
📝 Reported issues:

• [Flaky Test] should handle Enter across blocks #39763 in specs/editor/various/multi-block-selection.test.js
• [Flaky Test] should leave a scheduled page scheduled if canceled #47499 in specs/editor/various/switch-to-draft.test.js
• [Flaky Test] should revert a scheduled page to a draft if confirmed #47500 in specs/editor/various/switch-to-draft.test.js

[Mamaduka]

Thank you, @kevin940726!

The inline hints look much better now.