keyboard: Move row code to CcKeyboardShortcutRow

This adds a widget called `CcKeyboardShortcutRow`, sub-classing
`GtkListBoxRow`, to handle a shortcut row. This makes the implementation
a bit tidier, rather than handling it all in `CcKeyboardPanel`, and
allows the widgets that compose the row to be laid out in xml.

This is a prerequisite for moving the shortcuts to a new dialog.

panels/keyboard/cc-keyboard-shortcut-row.h

@@ -0,0 +1,37 @@
+/* cc-keyboard-shortcut-row.h
+ *
+ * Copyright (C) 2020 System76, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#pragma once
+
+#include <gtk/gtk.h>
+#include "cc-keyboard-item.h"
+#include "cc-keyboard-manager.h"
+#include "cc-keyboard-shortcut-editor.h"
+
+G_BEGIN_DECLS
+
+#define CC_TYPE_KEYBOARD_SHORTCUT_ROW (cc_keyboard_shortcut_row_get_type())
+
+G_DECLARE_FINAL_TYPE (CcKeyboardShortcutRow, cc_keyboard_shortcut_row, CC, KEYBOARD_SHORTCUT_ROW, GtkListBoxRow)
+
+
+CcKeyboardShortcutRow *cc_keyboard_shortcut_row_new (CcKeyboardItem*, CcKeyboardManager*, CcKeyboardShortcutEditor*, GtkSizeGroup*);
+
+G_END_DECLS