do not allow search results with more than 100k docs

a) they take a long time to compute
b) danger of OOM
c) they should drill down

performanceDb/src/main/java/org/lucares/performance/db/TagsToFile.java

@@ -129,6 +129,9 @@ public class TagsToFile implements AutoCloseable {
 		final List<TagSpecificBaseDir> result = new ArrayList<>();
 
 		final List<Doc> searchResult = db.search(query);
+		if (searchResult.size() > 100_000){
+			throw new IllegalStateException("Too many results.");
+		}
 
 		for (final Doc document : searchResult) {