Add some AbstractNamedGraph functionalities

[leburgel]

Some convenience AbstractNamedGraph functionalities that I ended up using quite often, so I though it could make sense to add them here. A summary of the (potential) additions:

• A function rename_vertices which allows renaming the vertices of an AbstractNamedGraph or AbstractNamedEdge given a Function or Dictionary name map. It is basically the same as the one in https://github.com/mtfishman/ITensorNetworks.jl/blob/main/examples/peps/utils.jl, with some minor adjustments to make it work for all currently existing AbstractNamedGraph subtypes. In particular, it seemed to make sense to allow renaming to change the vertex type for the case of NamedGraph.
• Constructors for all currently existing AbstractNamedGraph subtypes which just take a list of vertices, similar to how Graphs.Graph(::Integer) returns a graph with a given number of vertices and no edges.
• Equality for AbstractNamedGraphs, useful for checking if the underlying graph of two instances of a given data structure is the same.

[leburgel]

As per the suggestions above, I switched to a core map-like interface for rename_vertices for AbstractNamedEdge and AbstractNamedGraph, with a Dictionary name map as a special case. These now rely on an internal set_vertices routine defined for each concrete subtype.

[mtfishman]

Looks great, thanks a lot! Also thanks for adding all those tests, these packages have been undertested...