feat: GraphMinorAnalyzer -- graph minor theory operations and analysis

Edge contraction, vertex/edge deletion, minor sequences, K5/K3,3 minor
containment testing, Hadwiger number estimation (greedy), planarity
heuristic (Wagner's theorem), minor-closed family tests (forest,
outerplanar), edge subdivision, contraction degeneracy, text report.

Usage: new GraphMinorAnalyzer(graph).generateReport()
       analyzer.hasK5Minor(), analyzer.isPlanarHeuristic()
       analyzer.contractEdge(v1, v2), analyzer.hadwigerNumber()

45 tests.

Author: sauravbhattacharya001