fix: add --replace flag

[ycyaoxdu]

add one cluster in clusterset1 to clusterset2 (by overwrite)

this can be regarded as remove+add

Signed-off-by: ycyaoxdu [email protected]

[ycyaoxdu]

test output:

╰─$ clusteradm clusterset add set1 --clusters cluster1                                                                                                                 1 
Cluster cluster1 is already added into Clusterset set2, you can't add it to set1

╰─$ clusteradm clusterset add set1 --replace --clusters cluster1
Cluster cluster1 is added into Clusterset set1

[qiujian16]

/approve
/lgtm

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: qiujian16, ycyaoxdu

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [qiujian16]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment