feat(routes): preloading

[UberMouse]

Adds a preload function to a route, this is an optional idempotency-required function that can be used to kick off data preloading for a route before it has been matched

The function can be called automatically by links on click or hover, and when a route is matched right before it's broadcast

[github-actions[bot]]

:tada: This PR is included in version 4.3.0-beta.1 :tada:

The release is available on:

• npm package (@beta dist-tag)
• GitHub release

Your semantic-release bot :package::rocket:

[github-actions[bot]]

:tada: This PR is included in version 4.3.0 :tada:

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: