Add support for Safari

Here's an applescript function that prints out the number of open tabs.

```applescript
tell application "Safari"
count every tab of every window
end tell
```

https://discussions.apple.com/thread/250505964

Probably use https://github.com/andrewp-as-is/applescript.py to run it.

- Make the class run the applescript function
- Return the value to a column in the table -- will need to rework the db logic a bit