Improve local development for workspaces

Description

Fix blocking SSH connections (!9 - merged) introduces some convenience scripts in the MR description that allow to build and release a new helm chart onto your local k8s cluster. This is helpful for local development. We would like to adapt those scripts as part of this repo's workflow.

Acceptance Criteria

• Have a script that builds the current code changes and releases a new chart onto the local k8s cluster as a makefile target
• Have a script that reverts to the original release as a makefile target
• Have a script as a make target that will clean old dev images to prevent accumulating storage
• Add documentation highlighting the above local development support tooling

Impact

Faster feedback loop when developing the proxy locally. The existing local development setup does not feat nicely into the existing GDK | AGENT | RANCHER flow