x-ref #28987

Pagination used to have box shadow back in the days which required this property, but nowadays it's redundant. (see https://github.com/twbs/bootstrap/blame/0cd186183c5e18f0517d6037d53f29c56adbac72/less/pagination.less#L17)

- Remove IE10 background hack
- Ability to change the pseudo element
- Ability to change the z-index
- Remove pointer events, just inherit this

Add unit test from #28912 to v5

To fix RGBA borders overlapping issue.

fixes issue #28892

The cross icon was confusing since some browsers use it as a reset button.

Just firing the focus event isn't enough ... need to actually call the proper `focus()` method for it to actually do it...

* Add Error checking to prevent invalid breakpoint

Error checking to prevent invalid breakpoint name

* check type rather than value

* Revert "check type rather than value"

This reverts commit 04ab1e65.

* use of not rather than null

Co-Authored-By: Shohei Yoshida <fellows3@gmail.com>

Co-Authored-By: Shohei Yoshida <fellows3@gmail.com>

* Remove unused classes/styles and use utilities instead of specific styles
* Use `getElementById` instead of `querySelector`

- Add same advice about keyboard/AT handling to popovers as a callout; also add information about not adding excessive content or interactive controls (and the suggestion to opt for a modal)
- Tweak the tooltips callout for consistency

Notably:

* bundlesize 0.15.3 → ^0.17.2
* eslint-plugin-unicorn ^8.0.2 → ^9.0.0
* terser ^3.17.0 → ^4.0.0

Co-Authored-By: Martijn Cuppens <martijn.cuppens@gmail.com>

Co-Authored-By: Mark Otto <otto@github.com>