How to handle external packages needed for specific search methods?

[THinnerichs]

With more and more added functionality, we add more and more packages to HerbSearch that are specific to a specific search method. E.g. grammar_optimizer loads Clingo_jll. You will probably not need Clingo when running the simple getting started guide or only probabilistic searches. The number of packages quickly accumulates.

We should find a way to load those lazily when actually needed without making the entire system slower.

[ReubenJ]

Package Extensions offer one approach. We'd just need to bump the minimum julia version to 1.9+