Remove a namespace references and rely on helm flags

[ppawlowski]

Get rid of the namespace definition within the helm chart and give freedom to the OPS team to decide which namespace application should be created via --namespace helm parameter.

Tracking issue for:

• https://github.com/FlowFuse/helm/security/code-scanning/58
• https://github.com/FlowFuse/helm/security/code-scanning/60
• https://github.com/FlowFuse/helm/security/code-scanning/61
• https://github.com/FlowFuse/helm/security/code-scanning/62
• https://github.com/FlowFuse/helm/security/code-scanning/63
• https://github.com/FlowFuse/helm/security/code-scanning/78