Settings Rework

* Add JSON string configuration field to RGBController to store device-specific configurations
    * This JSON string holds both configuration and schema
    * Add settings schema tracking to SettingsManager
    * Implement dynamic settings widget that generates a settings UI based on a JSON schema
    * Implement SettingsManager callback for notifying of settings changes and settings schema updates
    * Always enable Entire Device zone option and use it to enable Edit Device
    * Rename SaveSizes to SaveConfiguration in ProfileManager and Sizes.json to Configuration.json
    * Add zone flag for indicating that a zone's geometry may change, informing profile manager to ignore this check
    * Remove Theme setting and Theme Manager, as this didn't work on most setups anyways and Qt6 has proper Windows dark theming

JsonUtils.h

@@ -0,0 +1,22 @@
+/*---------------------------------------------------------*\
+| JsonUtils.h                                               |
+|                                                           |
+|   JSON utility functions                                  |
+|                                                           |
+|   This file is part of the OpenRGB project                |
+|   SPDX-License-Identifier: GPL-2.0-or-later               |
+\*---------------------------------------------------------*/
+
+#pragma once
+
+#include <string>
+#include "nlohmann/json.hpp"
+
+class JsonUtils
+{
+public:
+    static bool JsonGetBool(nlohmann::json& val, std::string key, bool dft = false);
+    static int  JsonGetInt(nlohmann::json& val, std::string key, int dft = 0);
+    static std::string JsonGetString(nlohmann::json& val, std::string key, std::string dft = "", bool allow_empty = true);
+    static bool JsonParse(std::string json_string, nlohmann::json& json_ref);
+};