Playbook refactor to support App build and run containers

[achamayou]

The goals for this PR are to:

1. Provide a complete CI docker image for CCF applications, using the latest release: ccfciteam/ccf-app-ci-18.04-oe-0.9:0.10
2. Provide a lightweight runtime image for CCF applications, using the latest release ccfciteam/ccf-app-run-18.04:0.10
3. Preserve the common playbook infra as much as possible, to make it easy to set up/upgrade dev machines/env for both CCF itself and CCF apps

In another PR, 1 and 2 will be hooked up to the release process, and will push those images automatically on release.

[ghost]

app_containers_and_playbooks@8388 aka 20200515.10 vs master ewma over 50 builds from 7991 to 8377

[jumaffre]

LGTM! Could we write a comment at the top of the app_ci and app_run Dockerfiles so that we/others can quickly find out which one to use depending on what they want to do?

[achamayou]

@jumaffre yes, I need to expand the doc to cover the different scenarios, because the setup is also different depending on whether you want to build CCF itself or an app against a release.

We also could/should put out a version against our nightly, for CI across repos.

[achamayou]

This needs a follow up PR to:

1. Clean up README.md
2. Establish different quickstart entry points for users who want to use CCF vs contribute to CCF
3. Document the containers