feat: add dup plugin

[vash]

Adding the kubectl dup plugin for duplication of all types of kubernetes resources (inc. custom).

Three modes were added :

• Duplicate (on all resources)
• Duplicate + Edit (on all resources) - Opens editor to edit the manifest and creates the object upon saving.
• Debug - Duplicate complex resources (deploy,sts,cronjob,job) and pods,without probes with modified command
  to prevent the pod from exiting (requires tail binary in the container)

https://github.com/vash/dup

[fawaf]

seems somewhat similar to https://github.com/derailed/k9s/blob/master/plugins/duplik8s.yaml though this is more generic i think? might make sense to combine these 2 somehow

[vash]

Yes, I agree with you, I think it's up to the user to be able to choose which plugin suites their needs.
I am certain the creator of the currently approved plugin has something in mind that separates their use-cases, as similar as they are.

Given the use-case I referenced (#2563), I would think that although they are similar, this is still going to provide value to the community due to its generic nature and the ability to provide a feature that was in the works and was supposed to be supported as an internal function within K9s itself.

[vash]

@derailed Would appreciate if you or anyone else could have a look at it