Enable activating and deactivating the 'Firefox VPN'

[lesleyjanenorton]

This PR...

• Adds a new StateVPNOnPartial state to the controller for when the VPN client is also in StateOnPartial
• Adds a new ExtensionController to manage extension states (on, off, idle, connecting - no UI for connecting in this PR as we'll need some guidance from UX)
• Updates toolbarIcon, tabHandler, and the UI to use extensionController instead of VPNController (where sensible).
• Updates the ProxyHandler
  • Moves resolving the site contexts list into proxyMap into ProxyHandler, since that is where other siteContexts things are happening.
  • Subscribes to the VPN controller for loophole, server, and exit server location data to update the proxyMap.
  • Processes and exposes the localproxy and exit location data into arrays of proxyInfo objects as well as the proxyMap.
• Updates the RequestHandler:
  • Subscribes to ProxyHandler for updated localProxy, exitLocation, and proxyMap
  • Subscribes to extensionController state and uses extensionState properties bypassTunnel and useExitRelays to conditionally proxy all Firefox traffic, instead of only site specific traffic.

If we're generally good with the structure of these changes I will start unbreaking and adding tests.

[strseb]

r+wc

[strseb]

Also this needs type info please 👉 👈

this.#mProxyMap.value = result;
Is the only member access. I wonder if this should be static and
the caller should do
this.#mProxyMap.value = getProxyMap(newProxyMap, servers)

This way you can easy create tests for that, which would be neat :)

[strseb]

After reading a Tidbid more.
This property should be a computed Property, based on this.#mSiteContexts and vpnState.servers, no?

[lesleyjanenorton]

I had forgotten about ye' old computed properties! Makes sense. Would need to be based on vpncontroller.state, vpncontroller.servers, and siteContexts though.

[strseb]

If this was a computed property, we would not need to update this manually :)

[strseb]

This propsum is a bit suboptimal imho.
updateProxyInfoFromClient. Handles the following:
Sets ->
this.localProxyInfo = localProxy;
Sets ->
this.currentExitRelay = exitRelays;
But it does not do anything with them. So we should prefer to just grab the original value proxyHandler.currentExitRelays.value - (or create a private getter as shortcut).

Then you also have this.

    if (this.extState.useExitRelays) {
      this.defaultProxyInfo = exitRelays;
    } else {
      this.defaultProxyInfo = ProxyUtils.getDirectProxyInfoObject();
    }

However your,propertySum does not listen to changes to extState. I think that is why it's also duped in handleExtensionStateChanges?
So i think you can simply that all by just using one propertysum to update defaultProxyInfo whenever one of the dependants change:

propertySum(
proxyHandler.currentExitRelays,
extController.state,
(exitRelay, extState)=>{
   if (extState.useExitRelays) {
      this.defaultProxyInfo = exitRelays;
    } else {
      this.defaultProxyInfo = ProxyUtils.getDirectProxyInfoObject();
    }
}

And you can remove all the other dupe code to keep that up to date :)