This is recommended in the Coding Conventions guidelines [1].
Specifically, what's important here is checking that it meets the 'platform.Client' contract.

[1] https://github.com/redhat-developer/odo/wiki/Dev:-Coding-Conventions#verify-interface-compliance

…ckage

This paves the way to providing a different implementation for Podman

Current implementation relies on the Devfile object,
so it makes more sense to be in the libdevfile package.

Specifically, the 'StartPortForwarding' method
can now accept an explicit list of ports that needs to
be forwarded, if the caller can compute provide such information.

This is currently useful on Podman where the ports
(even the random ones) are known in advance.

As explained in [1], this helper sidecar container (aptly named "odo-helper-port-forwarding")
will hold the actual container/host ports mapping in the spec
(to overcome the limitation of using hostPort against a container app listening on the loopback interface);
this running container will be used to execute the actual port-forwarding commands (based on socat), e.g:

```
apiVersion: v1
kind: Pod
metadata:
  name: my-component-app
  labels:
    app: my-component-app
spec:
  containers:
  - name: runtime
    command: [ 'tail', '-f', '/dev/null']
    # Omitted for brevity, but imagine an application being executed by odo
    # and listening on both 0.0.0.0:3000 and 127.0.0.1:5858

  - name: odo-helper-port-forwarding
    image: quay.io/devfile/base-developer-image:ubi8-latest
    command: [ 'tail', '-f', '/dev/null']
    ports:
    - containerPort: 20001
      # A command will be executed by odo, e.g.: 'socat -d -d tcp-listen:20001,reuseaddr,fork tcp:localhost:3000'
      hostPort: 20001
    - containerPort: 20002
      # A command will be executed by odo, e.g.: 'socat -d -d tcp-listen:20002,reuseaddr,fork tcp:localhost:5858'
      hostPort: 20002

# ... Omitted for brevity
```

In this scope, port-forwarding from 20002 to 5858 for example will be equivalent of executing
a socat command in this helper container, like so:

socat -d tcp-listen:20002,reuseaddr,fork tcp:localhost:5858

In the command above, this will open up port 20001 on the helper container,
and forwarding requests to localhost:5858
(which would be in the 'runtime' container, part of the same Pod)

[1] redhat-developer#6510