Fix the issue meta backup is failed when symbolic links exist in meta dir.

[KanShiori]

What problem does this PR solve?

Close #2241

What is changed and how it works?

• Use the relative path to create a symbolic link when executing tiup cluster patch --overwrte.
• Support packaging symbolic links when executing tiup cluster meta backup.

Check List

Tests

• Patch the pd and check the symbolic link is a relative path.

$ ./tiup-cluster patch my-cluster pd-v5.1.0-linux-amd64.tar.gz --overwrite -R pd
...

$ ll /root/.tiup/storage/cluster/clusters/my-cluster/patch/
total 40M
-rw-r--r-- 1 root root 40M Aug 18 06:58 pd-b64365c.tar.gz
lrwxrwxrwx 1 root root  17 Aug 18 06:58 pd.tar.gz -> pd-b64365c.tar.gz

• Backup cluster meta.

$ /tiup-cluster meta backup my-cluster
successfully backup meta of cluster my-cluster on tiup-cluster_my-cluster_metabackup_2023-08-18T07-00-21Z.tar.gz

• Restore to a new cluster and check the symbolic link.

$ ./tiup-cluster meta restore my-cluster-restore tiup-cluster_my-cluster_metabackup_2023-08-18T07-00-21Z.tar.gz
meta of cluster my-cluster-restore didn't exist before restore
the given tarball was last modified at 2023-08-18T07:00:32Z
restore meta of cluster my-cluster-restore successfully.

$ ll /root/.tiup/storage/cluster/clusters/my-cluster-restore/patch
total 40M
-rw-r--r-- 1 root root 40M Aug 18 07:01 pd-b64365c.tar.gz
lrwxrwxrwx 1 root root  17 Aug 18 07:01 pd.tar.gz -> pd-b64365c.tar.gz

Release notes:

Fix the issue meta backup is failed when symbolic links exist in meta dir.

[codecov-commenter]

Codecov Report

Patch coverage: 14.29% and project coverage change: +0.11% 🎉

Comparison is base (f73a527) 55.97% compared to head (91a804e) 56.09%.

❗ Current head 91a804e differs from pull request most recent head 0dd5b49. Consider uploading reports for the commit 0dd5b49 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2255      +/-   ##
==========================================
+ Coverage   55.97%   56.09%   +0.11%     
==========================================
  Files         320      320              
  Lines       33866    33877      +11     
==========================================
+ Hits        18956    19000      +44     
+ Misses      12641    12606      -35     
- Partials     2269     2271       +2     

Flag	Coverage Δ
cluster	44.91% <14.29%> (+0.09%)	⬆️
dm	25.65% <0.00%> (-0.04%)	⬇️
playground	15.81% <0.00%> (+0.07%)	⬆️
tiup	15.90% <0.00%> (+0.02%)	⬆️
unittest	22.65% <0.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage Δ
pkg/utils/ioutil.go	54.67% <0.00%> (-1.31%)	⬇️
pkg/cluster/manager/patch.go	42.24% <40.00%> (-0.44%)	⬇️

... and 8 files with indirect coverage changes

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[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: kaaaaaaang

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-08-18 09:32:24.741726749 +0000 UTC m=+882709.290742735: ☑️ agreed by kaaaaaaang.