Cluster-api: Adopt KIND as cluster bootstrapper

[vincepri]

/kind feature

Describe the solution you'd like
In the AWS provider, we've been using kind to spin up ephemeral bootstrap clusters for clusterctl. It would be nice to replace minikube with kind and improve the developer experience. After chatting with @BenTheElder at KubeCon, seems there are ways to use it as a library.

[dims]

👍

[alejandrox1]

@vincepri could I help out with this?

[vincepri]

Sure, check with @detiber, I remember he expressed interest in working on it.

[detiber]

My initial thoughts were to introduce kind as an alternate bootstrapper alongside minikube rather than simply swap it out for the time being to avoid being too disruptive of a change to users.