tiup could not support "." in tidb cluster name?

[Fighter324]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do?

tiup cluster display cluster8.tidb.xxxx.com

2. What did you expect to see?

Starting component cluster: /home/tidb/.tiup/components/cluster/v1.3.2/tiup-cluster display cluster8.tidb.xxxx.com
Cluster type: tidb
Cluster name: cluster8.tidb.xxxx.com
Cluster version: v4.0.5
SSH type: builtin
Dashboard URL: http://10.200.xxxx:2379/dashboard

3. What did you see instead?
   Error: Cluster name 'cluster8.tidb.xxxx.com' is invalid (common.invalid_cluster_name)

The cluster name should only contains alphabets, numbers, hyphen (-) and underscore (_).
Error: run /home/tidb/.tiup/components/cluster/v1.4.4/tiup-cluster (wd:/home/tidb/.tiup/data/SZG5pIZ) failed: exit status 1

4. What version of TiUP are you using (tiup --version)?
   1.4.4 tiup
   Go Version: go1.16.4
   Git Ref: v1.4.4
   GitHash: 0d05073

[9547]

The cluster name should only contain alphabets, numbers, hyphen (-), and underscore (_). . is not supported.