[#390] frostfs-cli: Pass bearer token to Tree srv

* Add --bearer flag for "tree" subcommand

Signed-off-by: Airat Arifullin a.arifullin@yadro.com

cmd/frostfs-cli/modules/tree/root.go

@@ -32,6 +32,8 @@ const (
 	pathAttributeFlagKey = "pattr"
 
 	latestOnlyFlagKey = "latest"
+
+	bearerFlagKey = "bearer"
 )
 
 func initCTID(cmd *cobra.Command) {
@@ -42,4 +44,6 @@ func initCTID(cmd *cobra.Command) {
 
 	ff.String(treeIDFlagKey, "", "Tree ID")
 	_ = cmd.MarkFlagRequired(treeIDFlagKey)
+
+	ff.StringP(bearerFlagKey, "", "", "Path to bearer token")
 }