Add `serialize = TRUE` option to chunk apply functions

[kuwisdelu]

When TRUE, we serialize the data from matter objects to workers.

When FALSE, we only serialize the metadata and the data is loaded locally on the workers. (Note: This requires the host and workers see the same paths to the data files!)

[kuwisdelu]

Due to the processing overhead of subsetting a matter object (i.e., decompressing and re-compressing the atoms) this is probably not worth it relative to the overhead of serializing a single chunk.

Closing for now.