PersonAvatar weird border when azureId is invalid

**Describe the bug**
Noticed that personavatar shows an odd border when the azureid is invalid. Don't know if this is intended or if it should be allowed to pass in an invalid id.

**To Reproduce**
```TypeScript

```

**Expected behavior**
A placeholder icon similiar to the old fusion-component version:

**Screenshots**
size={AvatarSize.Small}
size={AvatarSize.Large}
size not set

**Desktop (please complete the following information):**
- OS: Windows
- Browser Edge, Chrome and Firefox

**Additional context**