Set hostname on Bottlerocket nodes during bootstrap process

[vignesh-goutham]

What would you like to be added:
Set hostname on Bottlerocket nodes during kubeadm bootstrap process. Bottlerocket now as an api that exposes setting to set the hostname.

Why is this needed:
Hostname of a node is usually set during kubeadm bootstrap process as a pre/post kubeadm command. This is used to identify nodes with ease. This is also the name that gets populated when running kubectl get nodes. In addition to this, the node name also gets used for sending DHCP requests.

[ahreehong]

aws/eks-anywhere-build-tooling#1858