Borrow DG Exporter from ISImporter experiment

IS [#38747319]
dgExportController and interactive 'exports' key

IS [#38747319]
Add export button to properties demo

IS [#38747319]
Try removing 'dimensions' param from 'initGame'

IS [#38747319]
Support complex default values in validator

[#40271865]

E.g.
defaultValue: {
  a: 1,
  b: 2,
  c: 3
}
Update validator tests to cover objects as default values

[#40271865]
Fix images displaying after clicking reset button

[#40204179]
Update neighbor-list API and tests

[#38274433]

New features will be useful when atom is removed.
make clean: always run: bundle install --binstubs

... in main and server directories
Add remove function to arrays module
Add early support of removing atoms

[#38274433]

It should work when there are no radial bonds or angular bonds.
Can be tested using console:
model.removeAtom(i);

Work in progress.
Add tests focused on adding and removing atoms

[#38274433]
Readme: update links to MD2D examples
Update radial bond matrix and results after removing an atom

[#38274433]
Add interactive for testing atoms removing

[#38274433]

It contains simple atoms as well as atoms connected with bonds.
Export timeseries to DG using ps, not fs

IS [#38747319]
gettable description for params and output props
units, label for custom interactive outputs&params
DG exporter: use nice labels for params&outputs

IS [#38747319]
Update IS/properties demo with units & labels

IS [#38747319]