Allow configurable ordering of modules at the same dependency level

ApplicationModules,ModuleSorter orders modules topologically, then orders all modules within the same dependency level (siblings, cousins...) lexicographically by ApplicationModuleIdentifier. Currently, the only way to customize ordering among modules on the same level is to rename the modules or force a dependency in order to impose a hierarchy between them.

Request: Add an extension point to customize ordering within each topological level while preserving dependency constraints. This would keep default behavior unchanged while allowing deterministic, intentional ordering among all modules that share a dependency level.

Use case: This would help, for example, control the order in which ApplicationModuleInitializers execute across modules in the same dependency level that otherwise have no hierarchical relationship between them.

Start with ApplicationModules and ModuleSorter, focusing on the topological ordering and the lexicographic ordering by ApplicationModuleIdentifier within each level. Trace how ApplicationModuleInitializers consume that order, then define an extension point that preserves dependency constraints while leaving the default ordering unchanged. Done means callers can deterministically customize same-level module ordering.