Add comprehensive unit tests for IRC command handling and message formatting

- Implemented IrcCommandHandlerTests to cover various IRC commands including PING, JOIN, PART, and authentication scenarios.
- Added IrcMessageFormatterTests to validate message formatting for different message types such as text, images, files, and audio.
- Created IrcMessageTests to ensure correct parsing of IRC messages and handling of various command formats.
- Introduced TestHelpers to facilitate testing with mock connections and streams, including a FakeChatService and FakeEncryptionService for simulating chat behavior.

src/Directory.Build.props

@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup>
-    <Version>0.2.4</Version>
+    <Version>0.2.5</Version>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <NoWarn>$(NoWarn);CS1591</NoWarn>
   </PropertyGroup>