Add class to get and store parameters for configuring FilteringAlgorithm

[claudiofantacci]

[claudiofantacci]

Implementation of this helper class committed in claudiofantacci@4bf9d01.
I'm not satisfied with it and I think I will make improvements before merging everything into master.

For example, I'm still thinking about whether keeping all the implicit conversion (useful to have simple instructions like int int_data = parameter_container["a label"]) or to replace them with explicit type cast (e.g. int int_data = parameter_container["a label"].as_int()). The second is more verbose but probably safer and transparent from the user perspective.
Also, conversions are currently not safe at runtime and throw when the required required type is not the one stored.