[iOS] Fix nullability warnings/errors caused by the feature invite

ios/sdk/src/JitsiMeetView.h

 
 @property (nonatomic, nullable, weak) id<JitsiMeetViewDelegate> delegate;
 
-@property (nonatomic, readonly) InviteController *inviteController;
+@property (nonatomic, readonly, nonnull) InviteController *inviteController;
 
 @property (nonatomic) BOOL pictureInPictureEnabled;
 

ios/sdk/src/invite/AddPeopleController+Private.h

 @interface AddPeopleController ()
 
 @property (nonatomic, strong) NSMutableDictionary* _Nonnull items;
-@property (nonatomic, weak) InviteController *owner;
+@property (nonatomic, weak, nullable) InviteController *owner;
 @property (nonatomic, readonly) NSString* _Nonnull uuid;
 
-- (instancetype)initWithOwner:(InviteController *)owner;
+- (instancetype _Nonnull)initWithOwner:(InviteController * _Nonnull)owner;
 
-- (void)inviteSettled:(NSArray<NSDictionary *> *)failedInvitees;
+- (void)inviteSettled:(NSArray<NSDictionary *> * _Nonnull)failedInvitees;
 
 - (void)receivedResults:(NSArray<NSDictionary*> * _Nonnull)results
                forQuery:(NSString * _Nonnull)query;

ios/sdk/src/invite/AddPeopleControllerDelegate.h

  * previously provided.
  */
 - (void)addPeopleController:(AddPeopleController * _Nonnull)controller
-          didReceiveResults:(NSArray<NSDictionary*> * _Nonnull)results
+          didReceiveResults:(NSArray<NSDictionary *> * _Nonnull)results
                    forQuery:(NSString * _Nonnull)query;
 
 /**

ios/sdk/src/invite/InviteController+Private.h

 
 @property (nonatomic, nullable) AddPeopleController *addPeopleController;
 
-@property (nonatomic) NSString *externalAPIScope;
+@property (nonatomic) NSString * _Nonnull externalAPIScope;
 
 @property (nonatomic, nullable, weak) Invite *inviteModule;
 
-- (instancetype)initWithExternalAPIScope:(NSString * _Nonnull)externalAPIScope
+- (instancetype _Nonnull)initWithExternalAPIScope:(NSString * _Nonnull)externalAPIScope
                          andInviteModule:(Invite * _Nonnull)inviteModule;
 
 - (void)beginAddPeople;
 
-- (void)endAddPeopleForController:(AddPeopleController *)controller;
+- (void)endAddPeopleForController:(AddPeopleController * _Nonnull)controller;
 
-- (void) invite:(NSArray *)invitees
+- (void) invite:(NSArray * _Nonnull)invitees
   forController:(AddPeopleController * _Nonnull)controller;
 
 - (void)inviteSettled:(NSString * _Nonnull)addPeopleControllerScope
-       failedInvitees:(NSArray *)failedInvitees;
+       failedInvitees:(NSArray * _Nonnull)failedInvitees;
 
 - (void)performQuery:(NSString * _Nonnull)query
        forController:(AddPeopleController * _Nonnull)controller;
 
 - (void)receivedResults:(NSString * _Nonnull)addPeopleControllerScope
                   query:(NSString * _Nonnull)query
-                results:(NSArray *)results;
+                results:(NSArray * _Nonnull)results;
 
 @end

ios/sdk/src/invite/InviteController.h

 
 @property (nonatomic, nullable, weak) id<InviteControllerDelegate> delegate;
 
-- (void)  invite:(NSArray *)invitees
-  withCompletion:(void (^)(NSArray<NSDictionary *> *failedInvitees))completion;
+- (void)  invite:(NSArray * _Nonnull)invitees
+  withCompletion:(void (^ _Nullable)(NSArray<NSDictionary *> * _Nonnull failedInvitees))completion;
 
 @end