Prevent stack overflows on large dependency graphs

tuist generate on large valid dependency graphs used to crash with a stack overflow in recursive graph processing. The recursive traversals in CircularDependencyLinter, GraphCircularDetector, topologicalSort, ModuleMapMapper, and StaticProductsGraphLinter have been replaced with iterative implementations that use explicit stacks, so deep acyclic graphs now generate successfully and keep their existing diagnostics, ordering, and lint behavior.