Application env specification should be a map, not list

Currently the application environment can be specified as a list resembling the list on the kubernetes spec

application/myapp/values.yaml
```yaml
harness:
env:
- name: A
value: avalue
- name: B
value: bvalue
```

The limitation of using a list is that values cannot be overridden in different environments, so if I want to change the A variable in values-dev.yaml I also have to specify B.

In order to make the change backwards compatible can add a new specification

```yaml
harness:
envmap:
A: avalue
B: bvalue
```

Start by locating how application/myapp/values.yaml and values-dev.yaml currently process the harness.env list, then trace the environment override behavior. Support the proposed harness.envmap form while preserving the existing list specification; done means variable A can be changed without repeating B and both formats remain usable.

Written by the indexing model from the issue text.