feat: Add the kubeconfig in toolbox

Created by: harrisonliu5

Signed-off-by: harrisonliu5 harrisonliu_5@163.com

What type of PR is this?

/kind feature

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes ##https://github.com/kubesphere/kubesphere/issues/4160

Special notes for reviewers:

Does this PR introduced a user-facing change?

NONE

Additional documentation, usage docs, etc.:

/assign @wansir