[EuiPagination] Extract PaginationButton creation

[thompsongl]

Summary

Fixes #5046, in which EuiPagination failed to update state in EuiResizableContainer. The problem was not with EuiResizableContainer specifically, but could occur anytime a pagination change resulted in a parent rerender. Because the internal PaginationButton component was created inside another component, it was recreated with old state on every rerender.

The solution here is to extract PaginationButton creation, eliminating rerender recreation.

See the to-be-reverted change in the first EuiResizableContainer example for verification.

Checklist

- [ ] Check against all themes for compatibility in both light and dark modes
- [ ] Checked in mobile

• Checked in Chrome, Safari, Edge, and Firefox

- [ ] Props have proper autodocs and playground toggles
- [ ] 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
• Reverted revert me docs commit

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_5048/

[thompsongl]

10:23:39 Errors on tp://localhost:9999/#/layout/resizable-container
10:24:18 [landmark-unique]: Landmarks must have a unique role or role/label/title (i.e. accessible name) combination
10:24:18 Help: https://dequeuniversity.com/rules/axe/4.1/landmark-unique?application=axe-puppeteer
10:24:18 Elements:
10:24:18 - #resizable-panel_59667c20-0038-11ec-b1bd-7d3c9fc90fde > .euiPanel--transparent.euiResizablePanel__content.euiResizablePanel__content--scrollable > .euiPagination
10:24:18 1 accessibility errors

CI errors will be resolved when the docs change is reverted

[cee-chen]

QA'd the fix and it looks great! Super impressed by the clean and elegant solution to the problem also, huge kudos. Feel free to revert the resizable documentation example - I'll approve after that.

I mostly have small comments/questions that are by no means blockers, but would def appreciate your thoughts!

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_5048/

[cee-chen]

Changes look great - thanks a million Greg!

I think resizable_container_basic.js changes still need to be reverted, but other than that looks GTG!

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_5048/

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_5048/