shared/gui: Don't consider non-content search results for previews

Not entirely ideal, since we may want to search for 'cake', and look at
a preview for 'cake.txt' even if there is no 'cake' inside.

But this will do for now

shared/searchresult.h

@@ -7,6 +7,7 @@ class SearchResult
   public:
 	FileData fileData;
 	QVector<unsigned int> pages;
+	bool wasContentSearch = false;
 };
 
 #endif // SEARCHRESULT_H

shared/sqlitesearch.cpp

@@ -213,6 +213,7 @@ QVector<SearchResult> SqliteSearch::search(const LooqsQuery &query)
 		throw LooqsGeneralException("SQL Error: " + dbQuery.lastError().text());
 	}
 
+	bool contentSearch = query.hasContentSearch();
 	while(dbQuery.next())
 	{
 		SearchResult result;
@@ -229,6 +230,7 @@ QVector<SearchResult> SqliteSearch::search(const LooqsQuery &query)
 				result.pages.append(page.toUInt());
 			}
 		}
+		result.wasContentSearch = contentSearch;
 		results.append(result);
 	}
 	return results;