F load identifiables from yaml

Summary

For https://gitlab.indiscale.com/caosdb/customers/leibniz-zmt/management/-/issues/60 and since we will need this all the time. Moves the loading of identifiabels from a yaml file from the crawler main to the CaosDBIdentifiableAdapter class.

Focus

Mainly refactoring, but also added a unit test for this.

Test Environment

Unit test should be sufficient.

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