PrmPkg/DxePrmModuleDiscoveryLib: Add initial host-based unit tests

Adds host-based unit tests for DxePrmModuleDiscoveryLib. This is
an initial set of support, more tests should be added in the
future.

Cc: Andrew Fish <afish@apple.com>
Cc: Kang Gao <kang.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Michael Kubacki <michael.kubacki@microsoft.com>
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Benjamin You <benjamin.you@intel.com>
Cc: Liu Yun <yun.y.liu@intel.com>
Cc: Ankit Sinha <ankit.sinha@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Acked-by: Michael D Kinney <michael.d.kinney@intel.com>
Acked-by: Liming Gao <gaoliming@byosoft.com.cn>
Acked-by: Leif Lindholm <quic_llindhol@quicinc.com>
Reviewed-by: Ankit Sinha <ankit.sinha@intel.com>

PrmPkg/Library/DxePrmModuleDiscoveryLib/PrmModuleDiscovery.h

@@ -24,4 +24,16 @@ typedef struct {
 
 #pragma pack(pop)
 
+/**
+  Creates a new PRM Module Image Context linked list entry.
+
+  @retval PrmModuleImageContextListEntry  If successful, a pointer a PRM Module Image Context linked list entry
+                                          otherwise, NULL is returned.
+
+**/
+PRM_MODULE_IMAGE_CONTEXT_LIST_ENTRY *
+CreateNewPrmModuleImageContextListEntry (
+  VOID
+  );
+
 #endif