[qt] Filter collates accents (Unicode NFD) (#4380)

Now "POKEMON" and "pokemon" are the same, and search's no longer case sensitive.
Maybe we could transliterate? But that would require icu which is a bit overkill.
Main point is to be able to search "Pokemon" (accent on 'e') without actually typing the accent

https://unicode.org/reports/tr15/

Signed-off-by: lizzie <[email protected]>

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
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- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4380
Reviewed-by: MaranBr <[email protected]>
Reviewed-by: CamilleLaVey <[email protected]>

src/yuzu/game/common.h

@@ -12,25 +12,29 @@ namespace Yuzu {
 
 inline bool ContainsAllWords(const QString& haystack, const QString& userinput) {
     const QStringList userinput_split = userinput.split(QLatin1Char{' '}, Qt::SkipEmptyParts);
-    return std::all_of(userinput_split.begin(), userinput_split.end(),
-                       [&haystack](const QString& s) { return haystack.contains(s); });
+    return std::all_of(userinput_split.begin(), userinput_split.end(), [&haystack](const QString& s) {
+        return haystack.contains(s);
+    });
 }
 
 inline bool FilterMatches(const QString& filter, const QStandardItem* item) {
     if (filter.isEmpty())
         return true;
 
+    auto const sluggify = [](const QString& s) {
+        QString o(s.normalized(QString::NormalizationForm_D).toLower());
+        return o.replace(QRegularExpression(QStringLiteral("[^a-z\\s]")), QStringLiteral(""));
+    };
+
+    const auto norm_filter = sluggify(filter);
     const auto program_id = item->data(GameListItemPath::ProgramIdRole).toULongLong();
-
-    const QString file_path = item->data(GameListItemPath::FullPathRole).toString().toLower();
-    const QString file_title = item->data(GameListItemPath::TitleRole).toString().toLower();
+    const QString file_path = sluggify(item->data(GameListItemPath::FullPathRole).toString());
+    const QString file_title = sluggify(item->data(GameListItemPath::TitleRole).toString());
     const QString file_program_id = QStringLiteral("%1").arg(program_id, 16, 16, QLatin1Char{'0'});
-
-    const QString file_name =
-        file_path.mid(file_path.lastIndexOf(QLatin1Char{'/'}) + 1) + QLatin1Char{' '} + file_title;
-
-    return Yuzu::ContainsAllWords(file_name, filter) ||
-           (file_program_id.size() == 16 && file_program_id.contains(filter));
+    const QString file_name = sluggify(file_path.mid(file_path.lastIndexOf(QLatin1Char{'/'}) + 1) + QLatin1Char{' '} + file_title);
+    return (ContainsAllWords(file_name, norm_filter)
+        || ContainsAllWords(file_title, norm_filter))
+        || (file_program_id.size() == 16 && file_program_id.contains(norm_filter));
 }
 
 } // namespace Yuzu