fix: general issues and minor bugs

Author: ReneSchwarzer

src/WebExpress.WebIndex/Storage/IndexStorageDocumentStore.cs

@@ -190,7 +190,7 @@ public void Delete(TIndexItem item)
             var segment = list.SkipWhile(x => x.Id != item.Id).FirstOrDefault();
 
             HashMap.Remove(segment);
-            foreach (var chunk in segment.ChunkSegments)
+            foreach (var chunk in segment?.ChunkSegments ?? [])
             {
                 Allocator.Free(chunk);
             }

src/WebExpress.WebIndex/Storage/IndexStorageSegmentHashMap.cs

@@ -204,6 +204,11 @@ public IEnumerable<IndexStorageSegmentItem> GetBucket(Guid id)
         /// found in the list.</returns>
         public bool Remove(IndexStorageSegmentItem segment)
         {
+            if (segment == null)
+            {
+                return false;
+            }
+
             var hash = segment.Id.GetHashCode();
             var index = (uint)hash % BucketCount;
             var bucket = GetBucket(index);