Adds a detached pipeline workflow template which runs the CI flow for both merge requests and branches without merge requests. An additional deployment template is added to implement the default webapp deployment flow.
The detached pipeline template in this MR is a copy of gitlab-ci/auto-devops-for-detached-pipelines.yml in MR uis/devops/uga/smi!221, so see that MR for a test pipeline based on the detached pipeline workflow template.
The deployment template in this MR is basically a copy of the SMI deploy CI config file with the webapp URLs converted to variables, and some optimisation of the rules.
