Adding additional files to make creation of experiments easier

See merge request !10

Use autosubmit expid -repo instead of rewriting the minimal.yml file.

Build only

See merge request !9

add an entry to load general packages from the module system at the very beginning of jobs, e.g. to load git

Including an icon.load_cmd for the cases where the build command includes a hash that can't be used for load. Defaults to the value of icon.build_cmd