chore: Suppress expected load errors (#1593)

- Add new `PluginPreconditionFailedException` to track cases where a plugin could not be loaded due to a precondition not being met.
  - Make `BannedPluginException` inherit from this
- Make `PluginPreconditionFailedException`s show as warnings in the log.

Dalamud/Plugin/Internal/Exceptions/BannedPluginException.cs

@@ -3,19 +3,14 @@ namespace Dalamud.Plugin.Internal.Exceptions;
 /// <summary>
 /// This represents a banned plugin that attempted an operation.
 /// </summary>
-internal class BannedPluginException : PluginException
+internal class BannedPluginException : PluginPreconditionFailedException
 {
     /// <summary>
     /// Initializes a new instance of the <see cref="BannedPluginException"/> class.
     /// </summary>
     /// <param name="message">The message describing the invalid operation.</param>
     public BannedPluginException(string message)
+        : base(message)
     {
-        this.Message = message;
     }
-
-    /// <summary>
-    /// Gets the message describing the invalid operation.
-    /// </summary>
-    public override string Message { get; }
 }

Dalamud/Plugin/Internal/Exceptions/PluginPreconditionFailedException.cs

@@ -0,0 +1,16 @@
+namespace Dalamud.Plugin.Internal.Exceptions;
+
+/// <summary>
+/// An exception to be thrown when policy blocks a plugin from loading.
+/// </summary>
+internal class PluginPreconditionFailedException : InvalidPluginOperationException
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="PluginPreconditionFailedException"/> class.
+    /// </summary>
+    /// <param name="message">The message to associate with this exception.</param>
+    public PluginPreconditionFailedException(string message)
+        : base(message)
+    {
+    }
+}