Allows invites to be sent to offline remotes (#28176)

* Allows invites to be sent to offline remotes

Invites sent to remotes marked as offline will be stored as pending,
and when the remote comes back online, it will process the invites as
part of the synchronization process.

* Update condition name for excluding confirmed invites

server/public/model/remote_cluster.go

@@ -33,6 +33,8 @@ const (
 
 var (
 	validRemoteNameChars = regexp.MustCompile(`^[a-zA-Z0-9\.\-\_]+$`)
+
+	ErrOfflineRemote = errors.New("remote is offline")
 )
 
 type Bitmask uint32

server/public/model/shared_channel.go

@@ -261,12 +261,13 @@ type SharedChannelFilterOpts struct {
 }
 
 type SharedChannelRemoteFilterOpts struct {
-	ChannelId       string
-	RemoteId        string
-	InclUnconfirmed bool
-	ExcludeHome     bool
-	ExcludeRemote   bool
-	IncludeDeleted  bool
+	ChannelId          string
+	RemoteId           string
+	IncludeUnconfirmed bool
+	ExcludeConfirmed   bool
+	ExcludeHome        bool
+	ExcludeRemote      bool
+	IncludeDeleted     bool
 }
 
 // SyncMsg represents a change in content (post add/edit/delete, reaction add/remove, users).