[Plugin][Enh] Implicit mapping of variables in tasks using containers

[JusteRaimbault]

Again related to #516 , some documentation is not super explicit (for python and julia compared to netlogo for example) on the fact that these tasks based on containers only accept mapped inputs and outputs. We should either:

• improve the doc
• add an implicit transformation to a mapped prototype when such an unmapped input/output is provided; this could introduce some confusion however, I am not sure this is the relevant thing to do

[romainreuillon]

Explicitly mapped outputs are useful. I would be in favor of the first solution.

[JusteRaimbault]

Ok I agree - leaving this open then to remind me to work on the doc