Add a field to neuron objects (inc. in a neuronlist)

Add an item to the the list object that comprises a neuron

add_field(x, entry, field = "bodyid", ...)

add_field_seq(x, entries, field = "bodyid", ...)

Arguments

x	a `nat::neuronlist` or `nat::neuron` object. It is assumed that this neuron has been read in by `neuprintr::neuprint_read_neurons` or possibly `catmaid::read.neurons.catmaid`.
entry	item to add.
field	name of new field, or field to overwrite.
...	Additional arguments passed to methods or eventually to `nat::nlapply`
entries	a vector/list of entries, the same length as `x`. Each neuron in `x` will have the entry in entries as the same index, added to it as `field`.

a neuron or neuronlist