Our search syntax is custom. Maybe switch to Lucence (https://lucene.apache.org/core/2_9_4/queryparsersyntax.html)?

Steps:

1. Dive into our powerful search syntax: https://docs.jabref.org/finding-sorting-and-cleaning-entries/search
2. Compare with lucene
3. Evaluate whether a switch is possible
4. Get rid off ANTLRv4
5. Add an ADR