oc: Update predecessor change list on saving

There were cases where only the change key was updated (GCS) or
others were the change key was updated with wrong info.

This changeset has as goal to update the predecessor change list
and, change key if required, on saving taking into account the latest information
given by the client in high level ROPs such as ImportMessageMove
or SetProperties, and merge it with information provided by the server
backend (IMAP server, SOGo DB) using `synchroniseCache`.

For more details about `PidTagChangeKey` and `PidTagPredecessorChangeList`
property values check [MS-OXCFXICS] Section 2.2.1.2

OpenChange/NSData+MAPIStore.m

@@ -22,6 +22,7 @@
 
 #import <NGExtensions/NSObject+Logs.h>
 
+#import "MAPIStoreTypes.h"
 #import "NSObject+MAPIStore.h"
 #import "NSString+MAPIStore.h"
 
@@ -29,6 +30,7 @@
 
 #undef DEBUG
 #include <stdbool.h>
+#include <libmapi/libmapi.h>
 #include <talloc.h>
 #include <util/time.h>
 #include <gen_ndr/exchange.h>
@@ -172,6 +174,38 @@ static void _fillFlatUIDWithGUID (struct FlatUID_r *flatUID, const struct GUID *
   return xid;
 }
 
+- (struct SizedXid *) asSizedXidArrayInMemCtx: (void *) memCtx
+                                         with: (uint32_t *) length
+{
+  struct Binary_r bin;
+  struct SizedXid *sizedXIDArray;
+
+  bin.cb = [self length];
+  bin.lpb = (uint8_t *)[self bytes];
+
+  sizedXIDArray = get_SizedXidArray(memCtx, &bin, length);
+  if (!sizedXIDArray)
+    {
+      NSLog (@"Impossible to parse SizedXID array");
+      return NULL;
+    }
+
+  return sizedXIDArray;
+}
+
+- (NSComparisonResult) compare: (NSData *) otherGlobCnt
+{
+  uint64_t globCnt = 0, oGlobCnt = 0;
+
+  if ([self length] > 0)
+    globCnt = *(uint64_t *) [self bytes];
+
+  if ([otherGlobCnt length] > 0)
+      oGlobCnt = *(uint64_t *) [otherGlobCnt bytes];
+
+  return MAPICNCompare (globCnt, oGlobCnt, NULL);
+}
+
 + (id) dataWithChangeKeyGUID: (NSString *) guidString
                       andCnt: (NSData *) globCnt;
 {