Use Codex styles for buttons in language overlay (attempt 2)

* Replace all instances of mw-ui markup with Codex markup
* Use codex-search-styles
* Where codex-search-styles is not installed (e.g. 1.39)
register an alias which points to @wikimedia/codex as that is
available.

Bug: T340255
Bug: T340257
Change-Id: I4f3ddfb68ea6c033ee7a49729187f4ddbc8abe5c

extension.json

@@ -209,9 +209,6 @@
 				"ext.uls.mediawiki",
 				"ext.uls.webfonts",
 				"mediawiki.api",
-				"mediawiki.ui.radio",
-				"mediawiki.ui.checkbox",
-				"mediawiki.ui.button",
 				"mediawiki.user"
 			]
 		},
@@ -278,8 +275,7 @@
 			"dependencies": [
 				"ext.uls.messages",
 				"ext.uls.preferences",
-				"jquery.uls.grid",
-				"mediawiki.ui.button"
+				"jquery.uls.grid"
 			]
 		},
 		"ext.uls.mediawiki": {
@@ -347,7 +343,7 @@
 			"dependencies": [
 				"mediawiki.api",
 				"mediawiki.jqueryMsg",
-				"mediawiki.ui.button",
+				"@wikimedia/codex",
 				"mediawiki.Uri"
 			],
 			"messages": [