Individual archives added by hand end up in the wrong location

Problem/Motivation

If a person creates an individual archive by hand, the resource file(s) added by hand do not end up in the right location.

They end up in the root of
dataset-archives/individual/

rather than the
dataset-archives/individual/[YEAR]/ that matches the 'dataset_modified' date set on the archive
The file name should also pickup the prefix of 'Y-m-d__dataset-id_'

This all works fine for archives that are created automatically be dataset updates, it is only for ones that are created by hand that are a problem

This move and rename will likely have to take place on presave.

Acceptance Criteria

1. Files are saved in the right location
2. Files are properly prefixed.

Testing steps