Update nuspec and build script to support `<license />` instead of the deprecated `<licenseUrl />`

* Add variable for dropdown-divider-margin-y

For us to reassign the nav-divider-margin-y variable here, we have to rearrange some of the variables.

Fixes #26660.

* bump bundlesize

With the current styles, it is not possible to nest a popover inside of
another popover if they have different placements because the arrow
styles of the parent popover will conflict with the arrow styles of the
child popover.

Fixes #25336

* Add table-hover-color variables
Fixes #26465

* Put $table-color to use outside _variables.scss

- Move 4.1 docs to 4.2
- Update versions everywhere to 4.1.3 with release script
- Manually bump the shorthand version in package.json
- Add 4.2 to the versions docs page
- Update some redirects
- Fix tests asset URLs
- Bump Nuget and more

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