Intermittent Content is Missing from Cook errors for objects with Niagara packages

Intermittently when cooking large licensee projects, an error is reported at the end of the cook:

LogCook: Error: Content is missing from cook. Source package referenced an object in target package but the object was stripped out of the target package when saved.
    Source package: <SourcePackage>
    Target package: <TargetPackage>
    Referenced object: <TargetPackage>.<TargetObject>:<TargetSubObject>

Errors of that form occur for multiple reasons, this JIRA is about the occurrence of this object for _GEN_VARIABLE objects within a package containing a UNiagaraSystem asset.

The issue with Niagara objects is caused by unstable naming of generated Niagara types, such as UNiagaraDataInterfaceSkeletalMesh. Objects of that type can be generated by Niagara code within a blueprint, and the name given is a generic ClassName_NumericSuffix, such as NiagaraDataInterfaceSkeletalMesh, UNiagaraDataInterfaceSkeletalMesh_1, UNiagaraDataInterfaceSkeletalMesh_2. The suffix is indeterministic depending on the state of the objects in the blueprint when the generated object is created.

We believe this is caused by the instance/template overrides on the Niagara component. In these functions:
NiagaraComponent::SynchronizeWithSourceSystem()
UNiagaraComponent::CopyParametersFromAsset()
UNiagaraComponent::ApplyOverridesToParameterStore()
A component's archetype will have a list of UNiagaraDataInterface, on load those may get recreated (because the source asset 'UNiagaraSystem' has changed)..the recreated ones might get different names (because we just do a NewObject with a blank name), and then when we instantiate the component we end up getting a mismatch between the data interfaces and their archetypes (because the assignment of the DI archetype is done via name through the chain of owners).

The result intermittently occurs during a cook. It requires a garbage collection in between the save of a target package containing Niagara assets and a source package that imports those Niagara assets.

FORT-885498 provides a synthetic repro of this case.