YT-CPPGHL-6: Implement the undirected hyperedge-list model

[SpectraL519]

Created the impl::undirected_hyperedge_list model class, which stores a list of hyperedges and their incident vertices and defines the following operations:

• Adding and removing vertices
• Adding and removing hyperedges
• Binding and unbinding vertices to hyperedges
• Retrieving the number of vertices incident with a given hyperedge
• Retrieving the set of vertices incident with a given hyperedge
• Validating whether a vertex is bound to a hyperedge

[SpectraL519]

ok