Bring Your Own Router

[mkrause]

We want to make it easy for consumers to integrate Baklava with any third party routing library.

Issue 1: There is a Link component in Baklava (which is a wrapper around an <a/>), but most apps will want to customize this component to use the relevant link component from their router library, but still get the styling from Baklava. Can we make it easier to do so?

Issue 2: how do we make it easy to replace any Link elements that are used inside of other Baklava components? See for example NavItem (related: #125).

Issue 3: what if there are Button elements used inside other components that the consumer wants to turn into a Link instead?

Issue 4: How do we integrate with things like query param providers for components like Tabs?