Plugin API hook for Shared Channel file attachment sync (#25874)

* option for auto inviting plugin to all shared channels.

* auto-invite remotes to shared channels when flag set

* fix unit test

* immediately ping new remotes; fix unique siteurl bug

* make i18n-extract

* fix translations

* plugin hooks for file attachments

* hook for profile image sync

* fix profile image sync

* fix unit test

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/app/remote_cluster.go

@@ -13,6 +13,7 @@ import (
 	"github.com/mattermost/mattermost/server/v8/platform/services/remotecluster"
 
 	"github.com/mattermost/mattermost/server/public/model"
+	"github.com/mattermost/mattermost/server/public/shared/mlog"
 )
 
 func (a *App) RegisterPluginForSharedChannels(opts model.RegisterPluginOpts) (remoteID string, err error) {
@@ -27,6 +28,11 @@ func (a *App) RegisterPluginForSharedChannels(opts model.RegisterPluginOpts) (re
 
 	// if plugin is already registered then treat this as an update.
 	if rc != nil {
+		a.Log().Debug("Plugin already registered for Shared Channels",
+			mlog.String("plugin_id", opts.PluginID),
+			mlog.String("remote_id", rc.RemoteId),
+		)
+
 		rc.DisplayName = opts.Displayname
 		rc.Options = opts.GetOptionFlags()
 
@@ -51,6 +57,11 @@ func (a *App) RegisterPluginForSharedChannels(opts model.RegisterPluginOpts) (re
 		return "", err
 	}
 
+	a.Log().Debug("Registered new plugin for Shared Channels",
+		mlog.String("plugin_id", opts.PluginID),
+		mlog.String("remote_id", rcSaved.RemoteId),
+	)
+
 	return rcSaved.RemoteId, nil
 }