Replicate network weights only to used NUMA nodes

On a system with multiple NUMA nodes, this patch avoids unneeded replicated
(e.g. 8x for a single threaded run), reducting memory use in that case.

Lazy initialization forced before search.

Passed STC:
https://tests.stockfishchess.org/tests/view/66a28c524ff211be9d4ecdd4
LLR: 2.96 (-2.94,2.94) <-1.75,0.25>
Total: 691776 W: 179429 L: 179927 D: 332420
Ptnml(0-2): 2573, 79370, 182547, 78778, 2620

closes https://github.com/official-stockfish/Stockfish/pull/5515

No functional change

src/thread.cpp

@@ -102,6 +102,8 @@ void Thread::run_custom_job(std::function<void()> f) {
     cv.notify_one();
 }
 
+void Thread::ensure_network_replicated() { worker->ensure_network_replicated(); }
+
 // Thread gets parked here, blocked on the condition variable
 // when the thread has no work to do.
 
@@ -400,4 +402,9 @@ std::vector<size_t> ThreadPool::get_bound_thread_count_by_numa_node() const {
     return counts;
 }
 
+void ThreadPool::ensure_network_replicated() {
+    for (auto&& th : threads)
+        th->ensure_network_replicated();
+}
+
 }  // namespace Stockfish