Remove package in subscribers YAML
In the YAML, when adding a subscriber the user has to fill the key
package which is part of the name of the library (without the initial
libsubscriber). In case of
SubscriberGnssFix it is
gnss_fix. This is not known by the user and this information is easily extracted from the type (removing "Subscriber" and changing each upper case char by "_" and the corresponding lower case).