Improve Asset Group to Asset UI

### Blockers/Dependencies
None

### Overview
REPLACE THIS TEXT -Text here that clearly states the purpose of this issue in 2 sentences or less.

### Action Items
- [ ] Allow autocreation of asset group if none is selected
- [ ] Show assets on Asset Group
- [ ] When add another, default to the previous Asset Group?
REPLACE THIS TEXT -If the issue has already been researched, and the course of action is clear, this will describe the steps. However, if the steps can be divided into tasks for more than one person, we recommend dividing it up into separate issues, or assigning it as a pair programming task.

### How to Manually Verify
REPLACE THIS TEXT - Describe how to manually verify either through UI or executing the code and inspecting.

### Automated Tests
Any automated tests?

### Resources/Instructions
REPLACE THIS TEXT -If there is a website which has documentation that helps with this issue provide the link(s) here.

该 issue 没有指出文件、入口点或测试。首先定位 Asset and Asset Group UI，以及创建或选择 group 的代码；确定列出的三种交互应如何工作，然后在 UI 中手动验证每种行为。

由索引模型根据 Issue 内容生成。