[Feature request] Introduce support for capacity reservation in AzureMachineSpec

[TrilokGeer]

/kind feature

Describe the solution you'd like

Currently, the AzureMachineSpec struct lacks support for capacity reservation, which limits users' ability to leverage capacity reservation benefits in Azure. Capacity reservation allows users to reserve capacity in advance, ensuring availability of resources when needed, and potentially providing cost savings.

Anything else you would like to add: Support capacity reservation by adding changes to

type AzureMachineSpec struct {
         .....
	// CapacityReservationGroupID specifies the capacity reservation group resource id that should be
	// used for allocating the virtual machine
	// +kubebuilder:validation:nullable
	// +opional
	CapacityReservationGroupID *armcompute.SubResource `json:"capacityReservationGroupID, omitempty"`
}

Environment: Azure Public Cloud

• cluster-api-provider-azure version: latest
• Kubernetes version: (use kubectl version): 1.27.4
• OS (e.g. from /etc/os-release): Fedora 39

[arkadeepsen]

/assign