Rename scalar-admin-k8s to scalar-admin-for-kubernetes

[supl]

Description

This PR renames scalar-admin-k8s to scalar-admin-for-kubernetes.

The original discussion is #20 (review) and the meeting (12/21) notes is: https://scalar-labs.atlassian.net/wiki/spaces/SD/pages/1822261303/2023-12-21+Meeting+notes+Scalar+Admin+for+Kubernetes

Related issues and/or PRs

#20

Changes made

• renamed CLI to scalar-admin-for-kubernetes-cli-{version}.jar
• renamed Docker image to ghcr.io/scalar-labs/scalar-admin-for-kubernetes:{version}
• renamed Java package to com.scalar.admin.kubernetes

Checklist

• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation to reflect the changes.
• Any remaining open issues linked to this PR are documented and up-to-date (Jira, GitHub, etc.).
• Tests (unit, integration, etc.) have been added for the changes.
• My changes generate no new warnings.
• Any dependent changes in other PRs have been merged and published.

[kota2and3kan]

LGTM! Thank you!

[feeblefakie]

LGTM! Thank you!