Multiple small enhancements

[sjahreis]

As we updated one of our ktorbase-based projects, we identified some small enhancements:

• add AppBaseUrl again (see bae404e)
• switch from logback to log4j (see build.gradle)
• add fontawesome to the frontend dependencies (see build.gradle)
• Bitbucket pipeline (see https://github.com/linked-planet/ktorbase/blob/master/bitbucket-pipelines.yml)
  • add environment uat
  • change notation of test, uat and prod to lower case
  • add submodule initialization (shouldn't matter if no submodule is present)
  • switch to linktimelabs/docker-build-kotlin-fullstack:latest image for build-step
  • create a CI pipeline
• Upgrade Gradle Wrapper to 7.1
• escape the image version parameter in deploy.sh (should be --parameter-overrides "[$PARAMETER_OVERRIDES\"ServiceImageVersion=$SERVICE_IMAGE_VERSION\"]")