api [nfc]: Make all remaining constructor arguments required

This completes the sweep for the point of style we added
to the README a few commits ago.

Author: gnprice

lib/api/model/initial_snapshot.dart

@@ -73,11 +73,11 @@ class InitialSnapshot {
   }
 
   InitialSnapshot({
-    this.queueId,
+    required this.queueId,
     required this.lastEventId,
     required this.zulipFeatureLevel,
     required this.zulipVersion,
-    this.zulipMergeBase,
+    required this.zulipMergeBase,
     required this.alertWords,
     required this.customProfileFields,
     required this.recentPrivateConversations,

lib/api/model/model.dart

@@ -179,7 +179,7 @@ class User {
     required this.timezone,
     required this.avatarUrl,
     required this.avatarVersion,
-    this.profileData,
+    required this.profileData,
     required this.isSystemBot,
   });
 
@@ -328,22 +328,22 @@ class Subscription {
     required this.renderedDescription,
     required this.dateCreated,
     required this.inviteOnly,
-    this.desktopNotifications,
-    this.emailNotifications,
-    this.wildcardMentionsNotify,
-    this.pushNotifications,
-    this.audibleNotifications,
+    required this.desktopNotifications,
+    required this.emailNotifications,
+    required this.wildcardMentionsNotify,
+    required this.pushNotifications,
+    required this.audibleNotifications,
     required this.pinToTop,
     required this.emailAddress,
     required this.isMuted,
-    this.isWebPublic,
+    required this.isWebPublic,
     required this.color,
     required this.streamPostPolicy,
-    this.messageRetentionDays,
+    required this.messageRetentionDays,
     required this.historyPublicToSubscribers,
-    this.firstMessageId,
-    this.streamWeeklyTraffic,
-    this.canRemoveSubscribersGroupId,
+    required this.firstMessageId,
+    required this.streamWeeklyTraffic,
+    required this.canRemoveSubscribersGroupId,
   });
 
   factory Subscription.fromJson(Map<String, dynamic> json) =>
@@ -406,7 +406,7 @@ sealed class Message {
     required this.contentType,
     required this.id,
     required this.isMeMessage,
-    this.lastEditTimestamp,
+    required this.lastEditTimestamp,
     required this.reactions,
     required this.recipientId,
     required this.senderEmail,
@@ -416,8 +416,8 @@ sealed class Message {
     required this.subject,
     required this.timestamp,
     required this.flags,
-    this.matchContent,
-    this.matchSubject,
+    required this.matchContent,
+    required this.matchSubject,
   });
 
   factory Message.fromJson(Map<String, dynamic> json) {
@@ -471,7 +471,7 @@ class StreamMessage extends Message {
     required super.contentType,
     required super.id,
     required super.isMeMessage,
-    super.lastEditTimestamp,
+    required super.lastEditTimestamp,
     required super.reactions,
     required super.recipientId,
     required super.senderEmail,
@@ -481,8 +481,8 @@ class StreamMessage extends Message {
     required super.subject,
     required super.timestamp,
     required super.flags,
-    super.matchContent,
-    super.matchSubject,
+    required super.matchContent,
+    required super.matchSubject,
     required this.displayRecipient,
     required this.streamId,
   });
@@ -573,7 +573,7 @@ class DmMessage extends Message {
     required super.contentType,
     required super.id,
     required super.isMeMessage,
-    super.lastEditTimestamp,
+    required super.lastEditTimestamp,
     required super.reactions,
     required super.recipientId,
     required super.senderEmail,
@@ -583,8 +583,8 @@ class DmMessage extends Message {
     required super.subject,
     required super.timestamp,
     required super.flags,
-    super.matchContent,
-    super.matchSubject,
+    required super.matchContent,
+    required super.matchSubject,
     required this.displayRecipient,
   });
 

lib/api/route/account.dart

@@ -32,7 +32,7 @@ class FetchApiKeyResult {
   FetchApiKeyResult({
     required this.apiKey,
     required this.email,
-    this.userId,
+    required this.userId,
   });
 
   factory FetchApiKeyResult.fromJson(Map<String, dynamic> json) =>

lib/api/route/events.dart

@@ -41,7 +41,7 @@ class GetEventsResult {
 
   GetEventsResult({
     required this.events,
-    this.queueId,
+    required this.queueId,
   });
 
   factory GetEventsResult.fromJson(Map<String, dynamic> json) =>

lib/api/route/realm.dart

@@ -52,7 +52,7 @@ class GetServerSettingsResult {
     required this.authenticationMethods,
     required this.zulipFeatureLevel,
     required this.zulipVersion,
-    this.zulipMergeBase,
+    required this.zulipMergeBase,
     required this.pushNotificationsEnabled,
     required this.isIncompatible,
     required this.emailAuthEnabled,
@@ -61,7 +61,7 @@ class GetServerSettingsResult {
     required this.realmName,
     required this.realmIcon,
     required this.realmDescription,
-    this.realmWebPublicAccessEnabled,
+    required this.realmWebPublicAccessEnabled,
   });
 
   factory GetServerSettingsResult.fromJson(Map<String, dynamic> json) =>