Refactor settings handling in ScriptAnalyzer

- Added a new `HashtableSettingsConverter` to convert inline PowerShell hashtables into a strongly typed `SettingsData`.
- Introduced `ISettingsParser` interface for different settings file formats.
- Implemented `Psd1SettingsParser` for parsing PowerShell data files (.psd1) into `SettingsData`.
- Created a new `Settings` class to centralize the logic for obtaining analyzer settings, supporting auto-discovery, presets, and inline hashtables.
- Removed the old `Settings` class and its associated logic
- Updated `Helper.cs` and `ScriptAnalyzer.cs` to accommodate changes in settings handling.
- Added `SettingsData` class to represent fully parsed and normalized settings.

Author: liamjpeters

Engine/Commands/InvokeFormatterCommand.cs

@@ -17,7 +17,7 @@ namespace Microsoft.Windows.PowerShell.ScriptAnalyzer.Commands
     public class InvokeFormatterCommand : PSCmdlet, IOutputWriter
     {
         private const string defaultSettingsPreset = "CodeFormatting";
-        private Settings inputSettings;
+        private SettingsData inputSettings;
         private Range range;
 
         /// <summary>

Engine/Formatter.cs

@@ -23,7 +23,7 @@ public class Formatter
         /// <returns></returns>
         public static string Format<TCmdlet>(
             string scriptDefinition,
-            Settings settings,
+            SettingsData settings,
             Range range,
             TCmdlet cmdlet) where TCmdlet : PSCmdlet, IOutputWriter
         {
@@ -81,9 +81,9 @@ private static void ValidateNotNull<T>(T obj, string name)
             }
         }
 
-        private static Settings GetCurrentSettings(Settings settings, string rule)
+        private static SettingsData GetCurrentSettings(SettingsData settings, string rule)
         {
-            return new Settings(new Hashtable()
+            return HashtableSettingsConverter.Convert(new Hashtable()
             {
                 {"IncludeRules", new string[] {rule}},
                 {"Rules", new Hashtable() { { rule, new Hashtable(settings.RuleArguments[rule]) } } }

Engine/Helper.cs

@@ -1501,6 +1501,11 @@ public static string[] ProcessCustomRulePaths(string[] rulePaths, SessionState s
                 return null;
             }
 
+            if (rulePaths.Length == 0)
+            {
+                return null;
+            }
+
             Collection<PathInfo> pathInfo = new Collection<PathInfo>();
             foreach (string rulePath in rulePaths)
             {

Engine/ScriptAnalyzer.cs

@@ -207,7 +207,7 @@ public void CleanUp()
         /// Update includerules, excluderules, severity and rule arguments.
         /// </summary>
         /// <param name="settings">An object of type Settings</param>
-        public void UpdateSettings(Settings settings)
+        public void UpdateSettings(SettingsData settings)
         {
             if (settings == null)
             {