Suite shard destination resolves from the selected test plan

When tuist test runs against a scheme with multiple test plans, the suite shard destination resolver threads the requested test plan through platform inference and simulator destination concretization. The resolver now asks buildGraphInspector.testableTarget(…) with the same testPlan the build-for-testing step used, so it picks the right platform-level testable target instead of one from a different plan. Inferred platform=iOS Simulator destinations are made concrete (with a simulator UDID) when Tuist can resolve one, fixing exit-code-70 failures during test enumeration.