* update border-radius mixins

Add $enable-rounded as a keyword argument to border-raidus mixins

* Update rounded classes

- use border-radius mixins to repleace !important
- use true for $enable-rounded for rounded classes
- Add `.rounded-sm` and `.rounded-sm`  #27934

* update borders docs

* Revert touch of dist files

* Revert change of border-radius mixins

* use !important in border-radius utilies classes

* update border radius classes keep only rounded-lg and rounded-sm

Since they are being build, no point in hardcoding the year.

Alternate take to #27683 that builds the modifier class based on min-width, such that list groups are stacked until the class's breakpoint is reached. This is less verbose, matches our primary responsive approach, and prevents an extra class. Unfortunately, I believe supporting flush list groups is too much code here, so I've skipped that and made a note in the docs.

Also added examples generate from our breakpoints data file with a protip for how to do equal width items.

- 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

This reverts commit af484dc1.