Script Generator: script definitions respository storage

As an instrument scientist (we do not expect users to do this) updating the script definitions for the script generator, I would like the repository of the script definitions to be well managed.

This ticket is to investigate and implement better repository management script definitions on the remote side i.e. the origin.

- Option 1: use site gitlab instance
- Will enable scientists to use fedids as their git author
- Prevents us from having to manage authorisation of scientists
- We will be able to track who has committed what to the repository
- Alternative: use our own instance

Acceptance criteria:

- Use of site gitlab instance investigate
- Agreed origin is implemented
- Current script definitions put into the repository
- The repository and processes for accessing the site gitlab instance are documented
- Plan for deploying a change of origin is created and if possible executed
- Repository is accessible to external users (read only)
- Authorisation management is minimised, but we are able to track who has committed what i.e. spudulike is not used