Move focus to Nework Details Panel when selecting "Network" tab with keyboard

**Steps to reproduce:**

```
Using "Tab" key navigate to "Network" and press "Enter" key
```

**Expected behavior:**

```
The focus should move to the Details panel like with Call Tree, Flame Graph etc
```

**Actual behavior:**

```
The focus remains on the "Network" tab.
```

┆Issue is synchronized with this [Jira Task](https://mozilla-hub.atlassian.net/browse/FP-101)