[Suggestion] Confusing usage for the terme "Famix" for MetaModel Generator

## Description and Observations
The MetaModel Builder implementation and related identifiers currently refer to "Famix" (e.g., `FamixMetamodelGenerator << #MooseModelGenerator` ). 
Using "Famix" in the builder's identifier is confusing as it suggested that all Metamodel are conformed or are extension of Famix. 
Maybe the `FamixMetamodelGenerator` should be renamed `MooseMetamodelGenerator`  ?


