Core: Ensure node name does not contain leading/trailing whitespace

[ghengeveld]

Issue: #13251

What I did

Primarily, this trims each part of the title (aka kind), after splitting it on /:

const groups = kind.split('/').map((part) => part.trim());

The .map(part => part.trim()) is what's added. Everything else in this PR is refactoring. I'll leave comments to clarify.

Pro tip: ignore whitespace changes when reviewing this 👍

How to test

• Is this testable with Jest or Chromatic screenshots? Yes, a unit test should be added.
• Does this need a new example in the kitchen sink apps? No
• Does this need an update to the documentation? No

If your answer is yes to any of these, please make sure to include it in your PR.

[tmeasday]

I'm surprised this didn't involve any test changes. Do we need a test for this case?

[ghengeveld]

I'm surprised this didn't involve any test changes. Do we need a test for this case?

Yes we do, but I'm not sure where to add it. This whole lib is untested.

[tmeasday]

This whole lib is untested

Untrue!

https://github.com/storybookjs/storybook/blob/0f7a3a07bedf44a62df6303b5f969e87b76e2471/lib/api/src/tests/stories.test.js

[ghengeveld]

@tmeasday I added a test.

[tmeasday]

LGTM