move example data for iso* packages to an isodata package dedicated to just data

[sebkopf]

to keep the functionality packages small and comply with CRAN guidelines for package sizes, it will be necessary to move some or all of the example data to a separate data only package, this can probably be one that works for the entire isoverse and is just isodata. example of how this was done in the past is here:

• https://journal.r-project.org/archive/2017/RJ-2017-026/RJ-2017-026.pdf
• https://github.com/geanders/hurricaneexposuredata