feat(Tooltip): add reference prop

Resolves #4430

docs/app/components/content/examples/tooltip/TooltipCursorExample.vue

@@ -0,0 +1,41 @@
+<script setup lang="ts">
+const open = ref(false)
+const anchor = ref({ x: 0, y: 0 })
+
+const reference = computed(() => ({
+  getBoundingClientRect: () =>
+    ({
+      width: 0,
+      height: 0,
+      left: anchor.value.x,
+      right: anchor.value.x,
+      top: anchor.value.y,
+      bottom: anchor.value.y,
+      ...anchor.value
+    } as DOMRect)
+}))
+</script>
+
+<template>
+  <UTooltip
+    :open="open"
+    :reference="reference"
+    :content="{ side: 'top', sideOffset: 16, updatePositionStrategy: 'always' }"
+  >
+    <div
+      class="flex items-center justify-center rounded-md border border-dashed border-accented text-sm aspect-video w-72"
+      @pointerenter="open = true"
+      @pointerleave="open = false"
+      @pointermove="(ev) => {
+        anchor.x = ev.clientX
+        anchor.y = ev.clientY
+      }"
+    >
+      Hover me
+    </div>
+
+    <template #content>
+      {{ anchor.x.toFixed(0) }} - {{ anchor.y.toFixed(0) }}
+    </template>
+  </UTooltip>
+</template>