aptly: Find and snapshot projects corresponding to updates and security

During the configuration format overhaul, this code was initially rewritten in a suboptimal way which involved snapshotting projects over and over multiple times with lots of error messages. Instead of deduplicating it and making it snapshot projects only once, this code was mistakenly dropped, which resulted in snapshot identifiers going out of sync between the main repository and updates/security.

Instead of attempting to snapshot everything, just build a map of OBS projects corresponding to different repositories of the same distribution:

v2024: apertis:v2024:target
v2024-updates: apertis:v2024:updates:sdk
v2024-security: apertis:v2024:security:development

and then run the snapshotting project on the list of projects extracted from this map.

The last component in the project name (target etc) is irrelevant here since the snapshotting code will snapshot all projects in the group at once anyway.

Fixes: 7b57c3f7 (aptly: Port internal functions and the hook to the new calling format)