chore: clean up a bunch of legacy styles (#5973)

* remove unused experimental-styles-within

* remove unused styles

* more cleanup + prepr

* Refactor nearly all legacy buttons to use ButtonStyled

* prepr

* Update MC account selector to modern version

* prepr

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Co-authored-by: Calum H. <calum@modrinth.com>

packages/ui/src/components/nav/NotificationPanel.vue

@@ -1,6 +1,6 @@
 <template>
 	<div
-		class="vue-notification-group experimental-styles-within"
+		class="vue-notification-group"
 		:class="{
 			'intercom-present': isIntercomPresent,
 			'location-left': notificationLocation === 'left',

packages/ui/src/components/nav/PopupNotificationPanel.vue

@@ -1,6 +1,6 @@
 <template>
 	<div
-		class="popup-notification-group experimental-styles-within"
+		class="popup-notification-group"
 		:class="{
 			'has-sidebar': hasSidebar,
 		}"