Backend API permissions

[kristianharju]

• Added NGINX environment variables that define API permissions on backends
• Updated backends to versions that include API permission implementation

[Jusaa]

When updating appVersion of a geoweb chart, you need to also update the default version in values.yaml (and README), otherwise the old value will actually be used.

appVersion in Chart.yaml is only used to show which appVersion is used when inspecting the Helm release itself and the versions.backend variable for the actual image used. This should be changed, probably by removing default versions.backend value and using the appVersion or version.backend conditionally but I don't remember the details.