Core/HotkeyManager: Fix group names in config

For some reason every button group was shoved into the same config
group called "Keys" which caused buggy behavior once someone tried to
have hotkeys with the same name in different groups. This fixes that,
and converts existing configs to the new group names so they don't get
reset.

Source/Core/Core/HotkeyManager.cpp

@@ -13,6 +13,8 @@
 
 #include "Common/Common.h"
 #include "Common/CommonTypes.h"
+#include "Common/FileUtil.h"
+#include "Common/IniFile.h"
 #include "Common/StringUtil.h"
 
 #include "InputCommon/ControllerEmu/Control/Input.h"
@@ -237,6 +239,43 @@ bool IsPressed(int id, bool held)
   return false;
 }
 
+// This function exists to load the old "Keys" group so pre-existing configs don't break.
+// TODO: Remove this at a future date when we're confident most configs are migrated.
+static void LoadLegacyConfig(ControllerEmu::EmulatedController* controller)
+{
+  IniFile inifile;
+  if (inifile.Load(File::GetUserPath(D_CONFIG_IDX) + "Hotkeys.ini"))
+  {
+    if (!inifile.Exists("Hotkeys") && inifile.Exists("Hotkeys1"))
+    {
+      auto sec = inifile.GetOrCreateSection("Hotkeys1");
+
+      {
+        std::string defdev;
+        sec->Get("Device", &defdev, "");
+        controller->SetDefaultDevice(defdev);
+      }
+
+      for (auto& group : controller->groups)
+      {
+        for (auto& control : group->controls)
+        {
+          std::string key("Keys/" + control->name);
+
+          if (sec->Exists(key))
+          {
+            std::string expression;
+            sec->Get(key, &expression, "");
+            control->control_ref->SetExpression(std::move(expression));
+          }
+        }
+      }
+
+      controller->UpdateReferences(g_controller_interface);
+    }
+  }
+}
+
 void Initialize()
 {
   if (s_config.ControllersNeedToBeCreated())
@@ -245,7 +284,7 @@ void Initialize()
   s_config.RegisterHotplugCallback();
 
   // load the saved controller config
-  s_config.LoadConfig(true);
+  LoadConfig();
 
   s_hotkey_down = {};
 
@@ -255,6 +294,7 @@ void Initialize()
 void LoadConfig()
 {
   s_config.LoadConfig(true);
+  LoadLegacyConfig(s_config.GetController(0));
 }
 
 ControllerEmu::ControlGroup* GetHotkeyGroup(HotkeyGroup group)
@@ -306,7 +346,7 @@ HotkeyManager::HotkeyManager()
   for (std::size_t group = 0; group < m_hotkey_groups.size(); group++)
   {
     m_hotkey_groups[group] =
-        (m_keys[group] = new ControllerEmu::Buttons("Keys", s_groups_info[group].name));
+        (m_keys[group] = new ControllerEmu::Buttons(s_groups_info[group].name));
     groups.emplace_back(m_hotkey_groups[group]);
     for (int key = s_groups_info[group].first; key <= s_groups_info[group].last; key++)
     {
@@ -321,7 +361,7 @@ HotkeyManager::~HotkeyManager()
 
 std::string HotkeyManager::GetName() const
 {
-  return std::string("Hotkeys") + char('1' + 0);
+  return "Hotkeys";
 }
 
 void HotkeyManager::GetInput(HotkeyStatus* const kb)