Live preview section of variable does not show the variable if a nested object

### Expected Behavior

If variable is
```
"animal": {
"dog": {
"name": "rover"
}
}
```
Selecting the variable defined as {{animal}} should show in the live preview the above text.

### Actual Behavior

The live preview shows `[object Object]`

### Reproduction Steps

1. Go to debug
2. Select cog gear next to env vars
3. Create new env var settings
4. Create the above structure.
5. Select close
6. Open a request or create a new one
7. Select the JSON tab, and add {{animal}} as a variable. It should turn purple.
8. select the purple "animal" object.
9. Look at "Live Preview" section.

### Is there an existing issue for this?

- [X] I have searched the [issue tracker](https://www.github.com/Kong/insomnia/issues) for this problem.

### Additional Information

_No response_

### Insomnia Version

2023.5.8

### What operating system are you using?

Windows

### Operating System Version

Windows 11

### Installation method

.exe install

### Last Known Working Insomnia version

Unknown

No files, tests, or entry points are named. Reproduce the issue in the Windows 11 Insomnia client using a nested environment variable, then trace the Live Preview handling for the selected JSON variable. Done means selecting {{animal}} displays its nested object content instead of [object Object].

Written by the indexing model from the issue text.