perf: optimize the operation button style of the entity component (#780)

#### What type of PR is this?

/kind improvement

#### What this PR does / why we need it:

优化 Entity 组件（数据列表）的操作按钮样式。

#### Which issue(s) this PR fixes:

Fixes https://github.com/halo-dev/halo/issues/2971

#### Screenshots:

before:

![image](https://user-images.githubusercontent.com/21301288/208065926-9e0fb332-4075-43cf-b75f-4d040c80ccfa.png)


after:

<img width="1658" alt="image" src="https://user-images.githubusercontent.com/21301288/208066185-a48d5f84-e451-4fc7-9eea-b152ddb8db86.png">



#### Special notes for your reviewer:

None

#### Does this PR introduce a user-facing change?


```release-note
优化 Console 端数据列表的操作按钮样式
```

packages/components/src/components/entity/Entity.vue

@@ -37,7 +37,8 @@ const classes = computed(() => {
       <div v-if="$slots.dropdownItems" class="entity-dropdown">
         <FloatingDropdown>
           <div
-            class="entity-dropdown-trigger group-hover:bg-gray-100"
+            class="entity-dropdown-trigger group-hover:bg-gray-200/60"
+            :class="{ '!bg-gray-300/60': isSelected }"
             @click.stop
           >
             <IconMore />