Reliable suite-granularity sharding for tuist test

tuist test suite-granularity shard plans no longer silently drop test targets. Tests are now enumerated from a machine-parseable JSON file written by xcodebuild, with deterministic per-target recovery and a whole-module backstop. Previously the same commit could report 44 of 69 targets one run and 12 the next, silently skipping tests. If a module cannot be enumerated after recovery the command fails loudly instead of pretending success.