Add POCSAG Receiver plugin

applications/plugins/pocsag_pager/protocols/protocol_items.c

@@ -0,0 +1,9 @@
+#include "protocol_items.h"
+
+const SubGhzProtocol* pocsag_pager_protocol_registry_items[] = {
+    &subghz_protocol_pocsag,
+};
+
+const SubGhzProtocolRegistry pocsag_pager_protocol_registry = {
+    .items = pocsag_pager_protocol_registry_items,
+    .size = COUNT_OF(pocsag_pager_protocol_registry_items)};