Deal with individual_local_identifier not found

[smthfrmn]

Depending on what Apps the input data have passed through, the individual_local_identifier may be missing or something else, like individual.local.identifier, so this line will fail the whole app: https://github.com/nilanjanchatterjee/parturition/blob/main/RFunction.R#L100

We should make this line more robust to error (setting the animal_id as blank or NULL if we can't find it)