[C2] Make configuration .yaml files optional

[ywarnier]

Currently, services.yaml adds a hard requirement on the presence of config/authentication.yaml, config/hosting_limits.yaml and config/plugins.yaml.

This is not desirable, as this implies having those files in Git, which means they would be overwritten by subsequent pulls or manual Chamilo updates.

Make the requirement optional (ignore_errors in services.yaml) and convert those current 3 files to *.dist.yaml. Only these *.dist.yaml will be present in Git. Upon install or migration, and if these files are not present already, the *.dist.yaml are copied to *.yaml.

• [] modify services.yaml to make loading optional
• [] rename *.yaml to *.dist.yaml
• [] add migration to create those *.yaml files from a copy of the *.dist.yaml
• [] add installation step to create those *.yaml files from a copy of the *.dist.yaml