Support multiple Data dictionaries

The current assumption is that there is exactly one data dictionary per project. This however conflicts with topics such as architecture synthesis and reuse that will create/use more than one data dictionary.

In this issue, the following changes should be performed:

• Relax constraints in the compositor to enable creating more than one data dictionary
• Update {ComponentArchitecture, DataDictionary}Utils.findDataDictionary() to return "right" DataDictionary, i.e the one that is already used for other elements in the same logical architecture
• Provide a solution to pick a data dictionary for the first type that is assigned within a logical architecture.

Testing

• Test model migrator that handles removal of DataDictionaryRefSpec annotation with attached copy of ACC.af3_23. The models in branch 4241 have already been migrated to fix the test suite
• Check that selecting a struct for a port in either of the data dictionaries defined in multipe_dd_test.af3_23 "locks" the data dictionary for the other. Setting both ports to an atomic data type should offer all data types again
• (Co-)simulation still works
• Code generation for the rovers works