Patterns: enable cross-browser support for pattern uploading (#64123)

* Uploading pattern JSON files was triggering an error in Firefox "categoryMap.values().find  is not a function".
categoryMap.values() method returns an iterator.
Iterator.find() doesn't have wide browser support. It doesn't work in Firefox, Safari and others.

Converting categoryMap.values() iterator to an array allow the use of find()

Co-authored-by: ramonjd <ramonopoly@git.wordpress.org>
Co-authored-by: andrewserong <andrewserong@git.wordpress.org>

packages/edit-site/src/components/add-new-pattern/index.js

@@ -173,9 +173,14 @@ export default function AddNewPattern() {
 						// When we're not handling template parts, we should
 						// add or create the proper pattern category.
 						if ( postType !== TEMPLATE_PART_POST_TYPE ) {
-							const currentCategory = categoryMap
-								.values()
-								.find( ( term ) => term.name === categoryId );
+							/*
+							 * categoryMap.values() returns an iterator.
+							 * Iterator.prototype.find() is not yet widely supported.
+							 * Convert to array to use the Array.prototype.find method.
+							 */
+							const currentCategory = Array.from(
+								categoryMap.values()
+							).find( ( term ) => term.name === categoryId );
 							if ( currentCategory ) {
 								currentCategoryId =
 									currentCategory.id ||