We don't support Opera 12, and Firefox's property was the unprefixed one.

Fix for issue #24117

* Offset option can be function (Popper.js)

* Fix...add function type for offset option

* Remove constants for popper config

* Optimize code. Remove foreach loop.

* Refactoring. Remove getOffset method

* Use `aria-selected` instead of `aria-expanded`
* Change tab.js to use `aria-selected` rather than `aria-expanded`
* Add `aria-orientation=vertical` to vertical tab list
* Remove dynamic tabs with dropdowns
* Fix non-interactive code examples
* Only set `aria-selected` on the `role="tab"` trigger - this stops `aria-selected` being incorrectly added to the `role="tabpanel"` itself (probably harmless, but nonetheless incorrect)

* fix(scrollspy): Handle nested navs when nav-link inside nav-item

* [scrolspy] Find only child .nav-link's inside .nav-item

* [scrollspyt] Add tests for nested navs with nav-link inside nav-item

* fix troy-o's in test

_adjustDialog should be called when the modal is first displayed to prevent it jumping position when the viewport is resized

Prevents the test from failing

* Adjust margin for sticky elements on modal

Previously white space was visible to the right of sticky elements due to right padding being added to the body. This fixes #23661.

* Add unit tests for margin of sticky elements on modal

element

When one uses say a carousel inside a tab, the `.active` selector previously matches the carousel ones too leading to broken tabs.

It's not the perfect solution but should the job for now.

Part of an update to align the naming schemes across our components.

- Renames .popover-title to .popover-header
- Renames .popover-content to .popover-body

Refs: #22092