chore: initialize fields

Author: DavidRouyer

src/Pipedrive.net/Models/Request/NewActivity.cs

@@ -34,7 +34,7 @@ public class NewActivity : IEntityWithCustomFields
         public long? PersonId { get; set; }
 
         [JsonProperty("participants")]
-        public List<Participant> Participants { get; set; }
+        public List<Participant> Participants { get; set; } = new List<Participant>();
 
         [JsonProperty("org_id")]
         public long? OrgId { get; set; }

src/Pipedrive.net/Models/Request/NewFile.cs

@@ -5,18 +5,25 @@ namespace Pipedrive
 {
     public class NewFile
     {
+        [JsonProperty("file")]
         public Stream File { get; set; }
-        
+
+        [JsonProperty("deal_id")]
         public long? DealId { get; set; }
 
+        [JsonProperty("person_id")]
         public long? PersonId { get; set; }
 
+        [JsonProperty("org_id")]
         public long? OrgId { get; set; }
 
+        [JsonProperty("product_id")]
         public long? ProductId { get; set; }
 
+        [JsonProperty("activity_id")]
         public long? ActivityId { get; set; }
 
+        [JsonProperty("note_id")]
         public long? NoteId { get; set; }
 
         public NewFile(Stream file)

src/Pipedrive.net/Models/Request/NewPerson.cs

@@ -15,10 +15,10 @@ public class NewPerson : IEntityWithCustomFields
         public long OrgId { get; set; }
 
         [JsonProperty("email")]
-        public List<Email> Email { get; set; }
+        public List<Email> Email { get; set; } = new List<Email>();
 
         [JsonProperty("phone")]
-        public List<Phone> Phone { get; set; }
+        public List<Phone> Phone { get; set; } = new List<Phone>();
 
         [JsonProperty("visible_to")]
         public Visibility VisibleTo { get; set; }