chore: Formalize 'route walkers' a little more

[johncowen]

Back in #3151 we introduced the concept of 'route walkers'. These walk over every single route in your entire routing tree, giving you the opportunity to mutate or otherwise tweak a piece of routing config from The Outside.

When we made #3151, we noted we'd added the 'route walker' concept plus 2 walkers at our 'vue' level (i.e. in our vue module), even though the 2 walkers are specific to our application module.

This PR splits the concept and the application level implementations using a $.routeWalkers dependency injection label.

This means we can dynamically add/remove different routeWalkers at the service container level, which will be very useful moving forwards.

---

I also added one more walker than automatically adds a 'props.routeName' property to all route components. You will still need to use defineProps{ routeName: string}() in order to access it, but at least you no longer need to manually add repetitive routing configuration to do this.

[netlify]

✅ Deploy Preview for kuma-gui ready!

Name	Link
🔨 Latest commit	56b5af7
🔍 Latest deploy log	https://app.netlify.com/sites/kuma-gui/deploys/6756b0a308b31d0008e3dc0b
😎 Deploy Preview	https://deploy-preview-3221--kuma-gui.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[schogges]

👍