Add label field to task definition

Label is an alternative name for task that replace it when printed in following context eg.:

- log: when given task is up to date and is skipped from execution
- log: when given task is NOT up to date (`--status` command)
- in `--summary` and `--list` commands output

task.go

@@ -272,7 +272,7 @@ func (e *Executor) RunTask(ctx context.Context, call taskfile.Call) error {
 
 		if upToDate && preCondMet {
 			if !e.Silent {
-				e.Logger.Errf(logger.Magenta, `task: Task "%s" is up to date`, t.Task)
+				e.Logger.Errf(logger.Magenta, `task: Task "%s" is up to date`, t.Name())
 			}
 			return nil
 		}