* add VERSION buildArg to Dockerfiles, default to current airbyte version but overwritable
* use VERSION env var consistently as Dockerfile buildArg, jar version, and tag
pass version and image_tag into docker build task function
* add github action for building and pushing an OSS branch for Cloud to consume
* allow AirbyteVersion to validate versions containing 'oss-branch' prefix
* change oss-branch prefix to dev for branch-based versions
* better action name
* add docker-compose-cloud.build.yaml to define minimum set of cloud images that are pushed by oss branch action
* update local dev docs to describe optional usage of VERSION env var
* make branch_version_tag input optional, if not provided, generates dev-<commit_hash>
* fix typo
* fix missed merge conflict
* update docker docs
* update integrationRunner isDev check