Fix SearchInfo's non-null MetaInfo being null when initialized or whe…

…n an extraction error occurs (#1141)

The meta info might have been null either when SearchInfo is first initialized, or when extractor.getMetaInfo() throws an exception in getInfo().
This caused NewPipe to crash instead of showing a nice error in https://www.reddit.com/r/youtube/comments/184ttmw/what_exactly_about_blue_whales_has_youtube_so/.

extractor/src/main/java/org/schabi/newpipe/extractor/search/SearchInfo.java

@@ -19,7 +19,7 @@ public class SearchInfo extends ListInfo<InfoItem> {
     private final String searchString;
     private String searchSuggestion;
     private boolean isCorrectedSearch;
-    private List<MetaInfo> metaInfo;
+    private List<MetaInfo> metaInfo = List.of();
 
     public SearchInfo(final int serviceId,
                       final SearchQueryHandler qIHandler,