[EuiDataGrid] Refactor & write unit tests for fullscreen control + Standardize 'fullscreen' copy

[cee-chen]

Summary

This is essentially a 2 part PR, both parts centered around the fullscreen behavior of EuiDataGrid:

1. [Tech debt] Refactors all disparate parts of our fullscreen logic (some previously lived in the main data_grid file, others in data_grid_toolbar) to a single selector hook/file, and writes missing unit tests for said fullscreen mode logic.

2. [Copy] closes [EuiDataGrid] Typo in fullscreen tooltip #5653 and addresses all other components to convert full(-)screen -> fullscreen per Caroline's comment

⚠️ I recommend following along by commit because the copy changes in particular touch a huge swath of files.

Test coverage

Before:

After:

QA

Other than the 'fullscreen' tooltip text, no fullscreen functionality should have changed as a result of this PR:

• Fullscreen mode button toggles correctly
• Escape key to exit fullscreen mode works correctly
• Ref setIsFullScreen demo should still work as before
• restrictBody class should be correctly applied to and removed from the body

Checklist

- [ ] Check against all themes for compatibility in both light and dark modes
- [ ] Checked in mobile
- [ ] Checked in Chrome, Safari, Edge, and Firefox
- [ ] Checked for accessibility including keyboard-only and screenreader modes
- [ ] Props have proper autodocs and playground toggles
- [ ] Added documentation
- [ ] Checked Code Sandbox works for any docs examples

• Added or updated jest and cypress tests
• Checked for breaking changes and labeled appropriately
• A changelog entry exists and is marked appropriately

[cee-chen]

@chandlerprall Does this warrant a changelog entry? The first part is definitely internal only, but I'm not sure we add entries for basic copy changes since in theory our i18n changelog should capture that 🤔

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_5680/

[chandlerprall]

Does this warrant a changelog entry?

The i18n keys changed, which should be mentioned and even constitutes a breaking change because existing translations will need to be updated to match the new keys.

[cee-chen]

👍 Gotcha, I hadn't seen previous changelog entries with mention of copy changes before so I wasn't sure. I can definitely add a breaking changelog.

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_5680/

[chandlerprall]

One more nit, otherwise changes LGTM. The new full_screen_selector & its test file should drop the underscore in full_screen to match it being one word everywhere else.

[cee-chen]

FWIW our many internal fullScreenX variables are also incorrectly cased in that point. But honestly I think it's easier to read 🙈 I'm not as fussed about internal-only var names though (vs English/human-readable sentences). No strong feelings either way so I'll change the filename at least!

[cee-chen]

Ohh that's right, the file name actually affects the i18n token name so this was a great call!

[chandlerprall]

Ohh that's right, the file name actually affects the i18n token name so this was a great call!

That side effect didn't occur to me, but even better! 😄

[chandlerprall]

Re-approving for good luck

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_5680/