A high-profile duel over rights to a legal database is playing out in state court in Boston. The warring parties are six former partners and the asbestos defense firm they left, allegedly taking with them high-value file management and other databases. The case, filed in November, raises the question: When partners leave, does a database that includes client information belong to the clients they take with them? Or to the old firm, which says it has invested heavily in developing the proprietary database?…