Template support for Docker Compose env substitution syntax

[iamwillbar]

Is your feature request related to a problem? Please describe

Docker Compose supports environment variable interpolation (https://docs.docker.com/reference/compose-file/interpolation/), e.g. ${VAR_NAME} or ${VAR_NAME:-DEFAULT_VALUE}, which isn't recognized by Portainer.

Describe the solution you'd like

In addition to looking for mustache syntax, e.g. {{VAR_NAME}}, look for Docker Compose environment variable interpolation as well.

Describe alternatives you've considered

Manual conversion of interpolation to mustache syntax.

Additional context

No response