atomsDataTable: supporting adding and removing atoms

[#55660284]

This makes it possible to easily view data for the atoms
in the DNA model that is diverging.
modeling-translation-extra-long-dna: enable keyboardHandlers

[#55660284]

So the model can be stepped forward and back using
the keyboard.

Combine this with turning iFrame mode off and open
the Atom data table and you can step forward and back
while inspecting atom properties.