fix: commit message not loaded after cherry-pick/revert with --no-commit (#2858)

* fix: commit message not loaded after cherry-pick/revert with `--no-commit`
* code_review: auto-load commit message

---------

Co-authored-by: leo <longshuang@msn.cn>

Author: JC-Chung

src/ViewModels/Repository.cs

@@ -481,7 +481,10 @@ public void Close()
         {
             var commitMessage = _workingCopy.CommitMessage;
             if (!string.IsNullOrEmpty(commitMessage) && _workingCopy.InProgressContext != null)
+            {
                 File.WriteAllText(Path.Combine(GitDir, "MERGE_MSG"), commitMessage);
+                commitMessage = string.Empty; // Clears this from ui-state, since it is already saved in MERGE_MSG file.
+            }
 
             _uiStates.LastCommitMessage = commitMessage;
             _uiStates.Save();

src/ViewModels/WorkingCopy.cs

@@ -817,6 +817,8 @@ private void UpdateInProgressState()
 
                 if (oldType != null && IsAutoLoadedCommitMessage())
                     CommitMessage = string.Empty;
+                else if (string.IsNullOrEmpty(_commitMessage))
+                    LoadCommitMessageFromFile(Path.Combine(_repo.GitDir, "MERGE_MSG"));
 
                 return;
             }