Add Toggl integration

[JoshuaRichards]

I thought it would be cool if there was a site blocker with a toggl integration.

Now, when you try to visit a blocked site, the extension checks toggl to see if you're on a break. If you are, it lets you through to visit the blocked site. I plan on not showing the disable and pause buttons in the popup. That way if I want to procastinate, I have to either track it or manually disable the blocker through settings. Either way it's a bit of a hassle unless I'm already on a break.

No hard feelings if you're not interested in merging something like this. It is a bit of change in scope. I just thought I'd give you the option. Thanks for your work by the way. It was super easy to make the changes I needed.

[raicem]

Oh wow, that looks very good. Thank you.

The idea to integrate 3rd party services is very interesting especially in the extension world.I would like to build it and try it out first and I would like to make sure nobody sees anything related to Toggl unless they are looking at the settings.

I'll get back to this PR for further inspection. Code looks super clean so I'd like to merge it. That might take a bit while. In the meantime, if you need any help building and using it in your local device I'd be happy to help.

[JoshuaRichards]

I've been using this for a couple weeks and just found a little bug so I figured I'd better update this PR with the fix.

Let me know if you'd like me to clarify anything about my changes.