Add the split configuration proposal

[diconico07]

As discussed during the Community Meeting, here is the split configuration proposal on its own.

This proposal aims to split the configuration object in two objects

This change is needed for or can facilitate the implementation of several existing proposals:

• 88

• 75

• 77

Moreover, while this proposal tries to be as small as possible and stick as close as possible to the current behavior, several future enhancements or changes can already be envisioned while working on this proposal (these are here as future possibilities, and will be their own proposals if we feel we want to pursue those):

• Allow a WorkloadConfiguration to trigger on Instances properties rather than the DiscoveryConfiguration it is linked to, this could allow workload to be scheduled to only a subset of the discovered devices, or spanning over multiple DiscoveryConfigurations;
• Share Instances between DiscoveryConfigurations, if multiple DiscoveryConfigurations discover the exact same device, we may want to merge those as one Instance owned by several DiscoveryConfigurations;