Drift detection: ignore certain fields when resources are deployed with ContinuousWithDriftDetection

[gianlucam76]

Is your feature request related to a problem? Please describe.
Consider the case where a Deployment is deployed using Sveltos along with Autoscaler.
In this scenario, Deployment spec.replicas field will be modified by Autoscaler.

Ideally we want Sveltos to detect a configuration drift (a change in the Deployment). But we don't want Sveltos to react to spec.replicas be modified (as that is expected to happen and it is not a configuration drift)

[oliverbaehler]

@gianlucam76 could you implement this? The code base is too complex for me tbh :D