Check Extended M-Identifiability
extmID(lambda, maxCard = length(observedNodes))a list consisting of a Boolean, whether the graph is sign-identifiable and if yes, a list consisting of the sets
adjacency matrix with number of cols = number of latent nodes, number of rows = number of observed nodes
(optional) maximum size of set W
Sturma, N., Kranzlmüller, M., Portakal, I., and Drton, M. (2025) Matching Criterion for Identifiability in Sparse Factor Analysis. arXiv:2502.02986l