MM-24595 Migrate API handler getChannelMember(s) to be compatible with local mode (#14533)

Co-authored-by: Ibrahim Serdar Acikgoz <serdaracikgoz86@gmail.com>
Co-authored-by: Miguel de la Cruz <miguel@mcrx.me>
Co-authored-by: mattermod <mattermod@users.noreply.github.com>

api4/api.go

@@ -275,6 +275,9 @@ func InitLocal(configservice configservice.ConfigService, globalOptionsFunc app.
 	api.BaseRoutes.TeamMember = api.BaseRoutes.TeamMembers.PathPrefix("/{user_id:[A-Za-z0-9]+}").Subrouter()
 
 	api.BaseRoutes.Channels = api.BaseRoutes.ApiRoot.PathPrefix("/channels").Subrouter()
+	api.BaseRoutes.Channel = api.BaseRoutes.Channels.PathPrefix("/{channel_id:[A-Za-z0-9]+}").Subrouter()
+	api.BaseRoutes.ChannelMembers = api.BaseRoutes.Channel.PathPrefix("/members").Subrouter()
+	api.BaseRoutes.ChannelMember = api.BaseRoutes.ChannelMembers.PathPrefix("/{user_id:[A-Za-z0-9]+}").Subrouter()
 
 	api.BaseRoutes.Plugins = api.BaseRoutes.ApiRoot.PathPrefix("/plugins").Subrouter()
 	api.BaseRoutes.Plugin = api.BaseRoutes.Plugins.PathPrefix("/{plugin_id:[A-Za-z0-9\\_\\-\\.]+}").Subrouter()