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.h

@@ -83,6 +83,8 @@ class Thread {
     void clear_worker();
     void run_custom_job(std::function<void()> f);
 
+    void ensure_network_replicated();
+
     // Thread has been slightly altered to allow running custom jobs, so
     // this name is no longer correct. However, this class (and ThreadPool)
     // require further work to make them properly generic while maintaining
@@ -146,6 +148,8 @@ class ThreadPool {
 
     std::vector<size_t> get_bound_thread_count_by_numa_node() const;
 
+    void ensure_network_replicated();
+
     std::atomic_bool stop, abortedSearch, increaseDepth;
 
     auto cbegin() const noexcept { return threads.cbegin(); }