Iterative graph traversals prevent stack overflow on large projects

Large valid Tuist dependency graphs no longer crash tuist generate with a stack overflow. Recursive graph traversals in CircularDependencyLinter, GraphCircularDetector, topologicalSort, ModuleMapMapper, and StaticProductsGraphLinter were replaced with iterative implementations that use explicit stacks, so deep dependency paths stay stack-safe. Diagnostics, caching, ordering, and linting behavior are preserved.