Add UI to configure keyboard-to-controller mapping (#308)

* Add UI to configure keyboard-to-controller mapping

* Add an optional "---fix" argument to format-checking script

* clang fix

---------

Co-authored-by: georgemoralis <giorgosmrls@gmail.com>

src/input/keys_constants.h

@@ -0,0 +1,30 @@
+// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+enum KeysMapping : int {
+    Start_Key = 0,
+    Select_Key,
+    LAnalogDown_Key,
+    LAnalogLeft_Key,
+    LAnalogUp_Key,
+    LAnalogRight_Key,
+    PS_Key,
+    RAnalogDown_Key,
+    RAnalogLeft_Key,
+    RAnalogUp_Key,
+    RAnalogRight_Key,
+    DPadLeft_Key,
+    DPadRight_Key,
+    DPadUp_Key,
+    DPadDown_Key,
+    L2_Key,
+    L1_Key,
+    Cross_Key,
+    R2_Key,
+    Circle_Key,
+    R1_Key,
+    Square_Key,
+    Triangle_Key
+};