Fix docker image builds, some GitHub actions, and copying of empty list of task tags

Fixed

• Fix building and pushing of Docker images to Docker Hub
• Fix GitHub Actions run-task argument and add missing wait-for-success command and argument
• Fix copying of task definition tags when the list of tags is empty
• Add missing desired_count_cmd and tag_env_var_cmd GitHub Actions commands

Included

• #267
• #270
• #271
• #273