Add binding.GetParametersGroups API [WIP]

[DedSec256]

[auduchinok]

@DedSec256 What's the state here?

[DedSec256]

@auduchinok, I'll try to finish it soon

[auduchinok]

@DedSec256 What do you think about splitting getting the parameter nodes and getting their names into separate APIs? Maybe something like this:

IReadOnlyList<IReadOnlyList<ITreeNode>> GetParameterNodes(ITreeNode node) string GetParameterName(ITreeNode node)

The current API does two unrelated enough things and it doesn't seem right.

[auduchinok]

A side note: we should try to build common interfaces that would remove this ITreeNode processing and use typed getters instead. That could be quite challenging due to different representations of parameters and may require us to change the tree structure, though.