Refactor access modifiers and relocate IPlugin implementation

Changed multiple classes and inner structures to `internal` for improved encapsulation. Moved the `IPlugin` interface to a new file to enhance modularity and maintain code organization. These changes aim to improve code maintainability and clarity.

Author: ivandrofly

source/Commas/EntryPoint.cs

@@ -45,56 +45,4 @@ public string DoAction(Form parentForm, string srtText, double frameRate, string
 
         return "";
     }
-}
-
-public interface IPlugin
-{
-    /// <summary>
-    /// Name of the plug-in
-    /// </summary>
-    string Name { get; }
-
-    /// <summary>
-    /// Text used in Subtitle Edit menu
-    /// </summary>
-    string Text { get; }
-
-    /// <summary>
-    /// Version number of plugin
-    /// </summary>
-    decimal Version { get; }
-
-    /// <summary>
-    /// Description of what plugin does
-    /// </summary>
-    string Description { get; }
-
-    /// <summary>
-    /// Can be one of these: file, tool, sync, translate, spellcheck
-    /// </summary>
-    string ActionType { get; }
-
-    /// <summary>
-    /// Shortcut used to active plugin - e.g. Control+Shift+F9
-    /// </summary>
-    string Shortcut { get; }
-
-    /// <summary>
-    /// This action of callsed when Subtitle Edit calls plugin
-    /// </summary>
-    /// <param name="parentForm">Main form in Subtitle Edit</param>
-    /// <param name="srtText">SubRip text</param>
-    /// <param name="frameRate">Current frame rate</param>
-    /// <param name="uiLineBreak"></param>
-    /// <param name="file">Current subtitle file name</param>
-    /// <param name="videoFile">Current video file name</param>
-    /// <param name="rawText">Subtitle raw format</param>
-    /// <returns>Dialog</returns>
-    string DoAction(Form parentForm,
-        string srtText,
-        double frameRate,
-        string uiLineBreak,
-        string file,
-        string videoFile,
-        string rawText);
 }

source/Commas/IPlugin.cs

@@ -0,0 +1,53 @@
+namespace Nikse.SubtitleEdit.PluginLogic;
+
+public interface IPlugin
+{
+    /// <summary>
+    /// Name of the plug-in
+    /// </summary>
+    string Name { get; }
+
+    /// <summary>
+    /// Text used in Subtitle Edit menu
+    /// </summary>
+    string Text { get; }
+
+    /// <summary>
+    /// Version number of plugin
+    /// </summary>
+    decimal Version { get; }
+
+    /// <summary>
+    /// Description of what plugin does
+    /// </summary>
+    string Description { get; }
+
+    /// <summary>
+    /// Can be one of these: file, tool, sync, translate, spellcheck
+    /// </summary>
+    string ActionType { get; }
+
+    /// <summary>
+    /// Shortcut used to active plugin - e.g. Control+Shift+F9
+    /// </summary>
+    string Shortcut { get; }
+
+    /// <summary>
+    /// This action of callsed when Subtitle Edit calls plugin
+    /// </summary>
+    /// <param name="parentForm">Main form in Subtitle Edit</param>
+    /// <param name="srtText">SubRip text</param>
+    /// <param name="frameRate">Current frame rate</param>
+    /// <param name="uiLineBreak"></param>
+    /// <param name="file">Current subtitle file name</param>
+    /// <param name="videoFile">Current video file name</param>
+    /// <param name="rawText">Subtitle raw format</param>
+    /// <returns>Dialog</returns>
+    string DoAction(Form parentForm,
+        string srtText,
+        double frameRate,
+        string uiLineBreak,
+        string file,
+        string videoFile,
+        string rawText);
+}

source/Commas/Main.cs

@@ -4,7 +4,7 @@
 
 namespace Commas;
 
-public partial class Main : Form
+internal partial class Main : Form
 {
     private readonly Subtitle _subtitle;
     private volatile bool _isProcessing;

source/Commas/Services/LmStudioClient.cs

@@ -5,7 +5,7 @@
 
 namespace Nikse.SubtitleEdit.PluginLogic;
 
-public class LmStudioClient : IDisposable
+internal class LmStudioClient : IDisposable
 {
     private readonly string _prompt;
     private readonly HttpClient _httpClient;
@@ -56,7 +56,7 @@ public async Task<string> SendAsync(string text)
 
     public void Dispose() => _httpClient.Dispose();
 
-    public class ChatCompletionRequest(bool stream, Message[] messages, double temperature)
+    internal class ChatCompletionRequest(bool stream, Message[] messages, double temperature)
     {
         [JsonProperty("stream")]
         public bool Stream { get; } = stream;
@@ -68,7 +68,7 @@ public class ChatCompletionRequest(bool stream, Message[] messages, double tempe
         public double Temperature { get; } = temperature;
     }
 
-    public class Message(string role, string content)
+    internal class Message(string role, string content)
     {
         [JsonProperty("role")]
         public string Role { get; } = role;
@@ -77,7 +77,7 @@ public class Message(string role, string content)
         public string Content { get; } = content;
     }
 
-    public class ChatResponse
+    internal class ChatResponse
     {
         [JsonProperty("model")]
         public string Model { get; set; }
@@ -86,7 +86,7 @@ public class ChatResponse
         public Choices[] Choices { get; set; }
     }
 
-    public class Choices
+    internal class Choices
     {
         [JsonProperty("index")]
         public int Index { get; set; }