Implemented loading multiple env files. Added logging.

[coenm]

First environment file is leading.

ie.

repository-specific-env-files:
- filename: '{var.RepoEnvironmentFile}'
  when: true
- filename: '%MY_SECRET_PATH%{backslash}github.env'
  when: '{empty}{StringContains({Repository.RemoteUrls}, "github")}'

will load all environment variables from {var.RepoEnvironmentFile} and after that all environment variables where the key was not already set by {var.RepoEnvironmentFile} from '%MY_SECRET_PATH%{backslash}github.env'