Pass non-trivial/large function args by reference

Fixes a bunch of `-Wclazy-function-args-by-ref` warnings. See
https://github.com/KDE/clazy/blob/master/docs/checks/README-function-args-by-ref.md
for details.

Most of these changes are automated, using the clazy fixit by setting
the `CLAZY_EXPORT_FIXES` before compilation and then running:

    $ mkdir /tmp/patch
    $ find ../src -iname "*.yaml" -exec mv {} /tmp/patch \;
    $ clang-apply-replacements /tmp/patch

1 files changed, 1 insertions, 1 deletions

diff --git a/src/library/basesqltablemodel.cpp b/src/library/basesqltablemodel.cpp
index cae6671923..bc5e40759a 100644
--- a/src/library/basesqltablemodel.cpp
+++ b/src/library/basesqltablemodel.cpp
@@ -792,7 +792,7 @@ CoverInfo BaseSqlTableModel::getCoverInfo(const QModelIndex& index) const {
     return coverInfo;
 }
 
-void BaseSqlTableModel::tracksChanged(QSet<TrackId> trackIds) {
+void BaseSqlTableModel::tracksChanged(const QSet<TrackId>& trackIds) {
     if (sDebug) {
         qDebug() << this << "trackChanged" << trackIds.size();
     }