Move cards and filters folder out of game (#6145)

* big move

* also move game_specific_terms

* fix imports

* alphabetize cmake

* fix build failure

* create database folder and move files into it

* fix includes

* run formatter

cockatrice/src/database/card_completer_proxy_model.cpp

@@ -0,0 +1,18 @@
+#include "card_completer_proxy_model.h"
+
+CardCompleterProxyModel::CardCompleterProxyModel(QObject *parent) : QSortFilterProxyModel(parent)
+{
+}
+
+bool CardCompleterProxyModel::filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const
+{
+    if (filterRegularExpression().pattern().isEmpty()) {
+        return true;
+    }
+
+    QModelIndex index = sourceModel()->index(sourceRow, 0, sourceParent);
+    QString data = index.data(Qt::DisplayRole).toString();
+
+    // Ensure substring matching
+    return data.contains(filterRegularExpression());
+}