chore: add "--path-prefix" flag to backuprepo create command

[zjx20]

ref to apecloud/kubeblocks#6874

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 57.14286% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 43.37%. Comparing base (3384634) to head (93a51eb).

❗ Current head 93a51eb differs from pull request most recent head 7392357. Consider uploading reports for the commit 7392357 to get more accurate results

Files	Patch %	Lines
pkg/cmd/cluster/config_observer.go	0.00%	3 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #294   +/-   ##
=======================================
  Coverage   43.36%   43.37%           
=======================================
  Files         217      217           
  Lines       29040    29043    +3     
=======================================
+ Hits        12594    12597    +3     
- Misses      14897    14898    +1     
+ Partials     1549     1548    -1     

Flag	Coverage Δ
unittests	43.37% <57.14%> (+<0.01%)	⬆️

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

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.