Create Hlt1 line name to number mapping within Allen

Currently, the list of selection line names is saved for the gather selections algorithm as part of the json configuration written in Allen. However, the mapping between selection names and integers used when writing the DecReports is not saved. Instead, the json file is parsed with this function in Moore when running HLT2 / Sprucing and a map between line names and integers is created here. This map is then used to decode the DecReports.

Instead, the mapping between selection names and integers should be written as part of the Allen configuration into the json file and only read in Moore. This will avoid a wrong mapping between names and integers on different systems / with different configurations.