Add new interaction utilities and role attr to Reboot (#30562)

- Adds .user-select-* utils from v5
- Adds button role attribute util, one of the top requested features in our issues for adding pointer cursors
- Adds new docs page to demonstrate both
- Includes Sass list for customizing user select

scss/utilities/_interactions.scss

@@ -0,0 +1,5 @@
+// stylelint-disable declaration-no-important
+
+@each $value in $user-selects {
+  .user-select-#{$value} { user-select: $value !important; }
+}