qt: Implement GUI dialog frontend for ProfileSelector

Presents profiles in a list, similar to switch.

src/yuzu/main.h

@@ -99,10 +99,12 @@ signals:
     // Signal that tells widgets to update icons to use the current theme
     void UpdateThemedIcons();
 
+    void ProfileSelectorFinishedSelection(std::optional<Service::Account::UUID> uuid);
     void SoftwareKeyboardFinishedText(std::optional<std::u16string> text);
     void SoftwareKeyboardFinishedCheckDialog();
 
 public slots:
+    void ProfileSelectorSelectProfile();
     void SoftwareKeyboardGetText(const Core::Frontend::SoftwareKeyboardParameters& parameters);
     void SoftwareKeyboardInvokeCheckDialog(std::u16string error_message);