Draft: Provide DHCP-less option with manual IPA networking config

What does this MR do and why?

This MR demonstrates how to setup a DHCP-less deployment and implements it in capm3-virt CI tests.

This requires and uses following changes:

• in sylva-capi-cluster, branch add_preprovisioning_network_data, add a optional field in baremetalhost declaration to set preprovisioningNetworkDataName and associated secret => sylva-projects/sylva-elements/helm-charts/sylva-capi-cluster!388.
• in libvirt-metal, branch add_enableDHCP_option provides a way to optionally disable DHCP for libvirt-metal VMs => sylva-projects/sylva-elements/container-images/libvirt-metal!77

Using these upstream branches and declaring preprov networking data in capm3-virt values for workload clusters, makes possible to deploy a WC without DHCP => https://gitlab.com/sylva-projects/sylva-core/-/pipelines/1355344850

Notes:

• this MR is based on !2515 (merged), changes versus main displayed in UI are larger than really needed until !2515 (merged) is merged.
• Management cluster can also be deployed without DHCP (not demonstrated here, but could be)
• Using scc baremetalhosts.xxx.ip_preallocations should allow to re-use same IP for pre-provisioning and provisioning (not tested, could be)

Related reference(s)

Partially answers #462

cc @hardys1 @matrohon @tmmorin @Electrogur @marc.bailly1 @baburciu