[scoped-custom-element-registry] Improve issues related to formAssociated (#581)

* `formAssociated` set to first definition setting
* use polyfill unconditionally and add registry to ShadowRootInit
* support `getName` on registry

---------

Co-authored-by: Steve Orvell <[email protected]>

Author: sorvell

packages/scoped-custom-element-registry/CHANGELOG.md

@@ -7,6 +7,20 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 <!-- ## Unreleased -->
 
+## [Unreleased]
+
+### Added
+
+- registry in ShadowRootInit; matches current proposal but customElements
+  remains supported for compatibility
+
+### Changed
+
+- polyfill always used; conditional installation blocked by need for spec
+
+- formAssociated set by first name's defining value or if
+  CustomElementRegistryPolyfill.formAssociated set contains name
+
 ## [0.0.9] - 2023-03-30
 
 - Update dependencies ([#542](https://github.com/webcomponents/polyfills/pull/542))