Fix several CSS compatibility issues in Safari (#841)

* Fix button margin default for Safari compatibility

* Add Safari vendor prefixes that are somehow still necessary

* Add workaround for Safari not rendering text selection

* Replace <h3> and <p> placeholder labels in floating menus with <TextLabel>

* Replace <span> elements with <TextLabel> and set its cursor for Safari

frontend/src/components/window/title-bar/WindowTitle.vue

@@ -1,6 +1,6 @@
 <template>
 	<LayoutRow class="window-title">
-		<span>{{ text }}</span>
+		<TextLabel>{{ text }}</TextLabel>
 	</LayoutRow>
 </template>
 
@@ -17,11 +17,15 @@
 import { defineComponent, type PropType } from "vue";
 
 import LayoutRow from "@/components/layout/LayoutRow.vue";
+import TextLabel from "@/components/widgets/labels/TextLabel.vue";
 
 export default defineComponent({
 	props: {
 		text: { type: String as PropType<string>, required: true },
 	},
-	components: { LayoutRow },
+	components: {
+		LayoutRow,
+		TextLabel,
+	},
 });
 </script>