Takes a keyword list of comma separated strings keyed by serializer name and converts the strings into lists of atoms. Implicitly removes any binary string that cannot be safely converted to an atom.

Example:

# Input
[user: "name,id,location", comment: "type"]

# Output
[user: [:name, :id, :location], comment: [:type]]

Given a the name of a serializer, will return a string that represents the type of the entity being processed.

Given a set of included relations, will return a normalized list of child relations. Implicitly filters out any relation in the normalized tree that cannot be safely converted from a binary string to an atom.