Explicitly configure Lightning CSS features, and prefer user browserslist over default browserslist (#11402)

* exclude `Features.LogicalProperties` lightningcss feature

We don't want this to automatically apply since we have dedicated
logical property based utilities already.

We also have a feature flag to toggle some utilities to make use of
logical property based ones.

This feature should be opt-in to prevent backwards compatibility (e.g.:
RTL sites that _did_ use a mr-4 explicitly).

* update default browserslist

* explicitly include/exclude Lightning CSS features

* update tests based on new browserslist and include/exclude features from Lightning CSS

* update integration tests

* prefer user browserslist, fallback to built-in browserslist

* always include Nesting

If a custom browserslist config is used, then we don't explicitly set
the include/exclude features from Lightning CSS (except for nesting, we
always want to process nesting)

* ensure to fallback to the current working directory

* update changelog

tests/plugins/fontSize.test.js

@@ -168,7 +168,7 @@ test('font-size utilities can include a line-height modifier', () => {
         font-size: 12px;
         line-height: 21px;
       }
-      @media (width >= 768px) {
+      @media (min-width: 768px) {
         .md\:text-\[19px\]\/8 {
           font-size: 19px;
           line-height: 32px;