ci: Use helm for deployment to clusters

[ppawlowski]

Description

This PR changes the way how the FlowFuse Cloud containers are deployed to environments. The approach is changed from kubectl to helm.
The whole idea is to update image values for particular environments stored in the FlowFuse/CloudProject and let FlowFuse Cloud deployment workflow to run the actual update via the helm chart. Due to this fact, PR should be merged after https://github.com/FlowFuse/CloudProject/pull/372 .
At this moment workflow is crafted without the DRY approach and by readapting existing reusable workflows created for different purposes. In the future, this should be changed to follow DRY principles.

!!! Current configuration relies on unreleased reusable workflow feature - workflow should be updated once the feature is released.

Related Issue(s)

https://github.com/FlowFuse/CloudProject/issues/230

Checklist

• I have read the contribution guidelines
• Suitable unit/system level tests have been added and they pass
• Documentation has been updated
  • Upgrade instructions
  • Configuration details
  • Concepts
• Changes flowforge.yml?
  • Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production

Labels

• Backport needed? -> add the backport label
• Includes a DB migration? -> add the area:migration label

[hardillb]

Leaving for @ppawlowski to merge tomorrow