keep track of objects definition outside containers

[jimy-byerley]

ATM in branch rewrite, if you run the following sample code once and select one of the cubes in l, uimadcad will highlight l as it is the container variable, but also aor b because it is the definition statement of the selected object in l

a = brick(vec3(0), vec3(1))
b = brick(vec3(1), vec3(2))
print(Axis(O,Z))
l = [a, b, Axis(O,X)]

However it you reexecute the same code juste after, the parcimonial interpreter will restore the previous values of a, b and l with different mesh instances each (hence different ids). Because if this when selecting the cubes in l will no more highlight the a and b statements (they are no more related by their object id())

It could be very helpful to still highlight the statements creating the contained objects like a and b, but requires changing the way we track objects origins in the intepreter resulting scope ...