Full SPA support

[alexanderkirtzel]

Describe the bug
When using a SPA (build with React for example) and loading a new page no page view event gets fired 😱

To Reproduce
Steps to reproduce the behavior:

1. Go to elbwalker.com
2. Click on any internal link
3. See that no new page view event occurs

Expected behavior
I want SPA pages to behave like regular websites when loading a new page as soon as the url changes. The same page view event that would be triggered on a complete reload of the page should appear when I use an internal link.

Additional context
Take care about a possible duplicate initialization!

[alexanderkirtzel]

The walker supports SPAs with a custom tweak now. Just fire a walker run event every time a pageview takes place. This will tell the walker to re-initialize as it would be a regular pageview