[RF] AquaMai configuration refactor (#82)

更新了配置文件格式，原有的配置文件将被自动无缝迁移，详情请见新的配置文件中的注释（例外：`SlideJudgeTweak` 不再默认启用）
旧配置文件将被重命名备份，如果更新到此版本遇到 Bug 请联系我们

Updated configuration file schema. The old config file will be migrated automatically and seamlessly. See the comments in the new configuration file for details. (Except for `SlideJudgeTweak` is no longer enabled by default)
Your old configuration file will be renamed as a backup. If you encounter any bug with this version, please contact us.

AquaMai/AquaMai.Config/Attributes/ConfigSectionAttribute.cs

@@ -0,0 +1,21 @@
+using System;
+
+namespace AquaMai.Config.Attributes;
+
+[AttributeUsage(AttributeTargets.Class)]
+public class ConfigSectionAttribute(
+    string en = null,
+    string zh = null,
+    // It will be hidden if the default value is preserved.
+    bool exampleHidden = false,
+    // A "Disabled = true" entry is required to disable the section.
+    bool defaultOn = false,
+    // NOTE: You probably shouldn't use this. Only the "General" section is using this.
+    //       Implies defaultOn = true.
+    bool alwaysEnabled = false) : Attribute
+{
+    public ConfigComment Comment { get; } = new ConfigComment(en, zh);
+    public bool ExampleHidden { get; } = exampleHidden;
+    public bool DefaultOn { get; } = defaultOn || alwaysEnabled;
+    public bool AlwaysEnabled { get; } = alwaysEnabled;
+}