GameBrowser: Show the network folder as Network, with its own icon

The path display says Network instead of \\, and the folder button in
the drive list gets the new I_NETWORK icon and a translated name.

images.svg also picks up I_TOGGLE_ON and I_TOGGLE_OFF, not used yet.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

UI/UIAtlas.cpp

@@ -203,6 +203,7 @@ static const ImageMeta g_uiImageIDs[] = {
 	{"I_ARCHIVE_7Z", false},
 	{"I_ARCHIVE_RAR", false},
 	{"I_DOWNLOAD", false},
+	{"I_NETWORK", false},
 };
 
 static std::string PNGNameFromID(std::string_view id) {