Clarify how we make simulations over tables or singleton-alike input types

[VEZY]

We can use any input type to run!, but it is not clear how PlantSimEngine handles time-steps here. For example a user could use a type that is compatible with the Tables.jl interface but that is in fact just one time-step.

To resolve this issue, I propose to implement a trait for the inputs, so users will have the possibility to define how PlantSimEngine handles their types just by defining if its a table-alike object or a singleton.