Fixed BACnet/SC secure connect VMAC, UUID, and initialization sequence (#1142)

* Refactored the BACnet/SC datalink initialization order by moving certificate file checks and hub connection registration to occur after datalink initialization
* Replaced stdlib rand() with platform-specific cryptographically secure random functions (RtlGenRandom for Windows, getrandom for Linux, arc4random_buf for BSD) to generate UUID and VMAC addresses, preventing duplicates that broke connections
* Enabled conditional debug output in BACnet/SC components when BUILD=debug is specified

Makefile

@@ -62,7 +62,7 @@ ethernet:
 # see .github/workflows/gcc.yml
 .PHONY: bsc
 bsc:
-	$(MAKE) BACDL=bsc -s -C apps all
+	$(MAKE) LEGACY=true BACDL=bsc -s -C apps all
 
 .PHONY: apps
 apps:
@@ -226,7 +226,11 @@ server-mini:
 
 .PHONY: sc-hub
 sc-hub:
-	$(MAKE) BACDL=bsc -s -C apps $@
+	$(MAKE) LEGACY=true BACDL=bsc -s -C apps $@
+
+.PHONY: sc-hub-debug
+sc-hub-debug:
+	$(MAKE) LEGACY=true BACDL=bsc BUILD=debug -s -C apps sc-hub
 
 .PHONY: mstpcap
 mstpcap: