[Fix] - Kubeconfig merge needs user and cluster

[Ramilito]

Description

When merging and not using kubeconfig env variable, the resulting cached files don't have cluster and user in them. This PR adds those so they can be more complete. Results:

Fixes # (issue)

46 Fixes part of this

Type of change

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

How Has This Been Tested?

Tested locally by using it for a while

[nicmr]

Hi, thanks for adding me as a reviewer 😊 I'm quite busy this week but I'll have a look this Saturday!

[Ramilito]

Ive been running with this for a while and only noticed one issue, the kcd command doesn't permanently set it, I'm guessing it's because the merged files isn't known to kubectl. Will try setting the --kubeconfig command dynamically and see if it helps