revert!: remove Squash Children into Here

Since `Children` is an ambiguous word for commits to a multi-branch repository, and users can do the same job with the `Interactive Rebase` feature, this context menu entry will be removed.

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/Resources/Locales/en_US.axaml

@@ -143,7 +143,6 @@
   <x:String x:Key="Text.CommitCM.Reword" xml:space="preserve">Reword</x:String>
   <x:String x:Key="Text.CommitCM.SaveAsPatch" xml:space="preserve">Save as Patch...</x:String>
   <x:String x:Key="Text.CommitCM.Squash" xml:space="preserve">Squash into Parent</x:String>
-  <x:String x:Key="Text.CommitCM.SquashCommitsSinceThis" xml:space="preserve">Squash Children into ${0}$</x:String>
   <x:String x:Key="Text.CommitDetail.Changes" xml:space="preserve">CHANGES</x:String>
   <x:String x:Key="Text.CommitDetail.Changes.Count" xml:space="preserve">changed file(s)</x:String>
   <x:String x:Key="Text.CommitDetail.Changes.Search" xml:space="preserve">Search Changes...</x:String>

src/Resources/Locales/zh_CN.axaml

@@ -147,7 +147,6 @@
   <x:String x:Key="Text.CommitCM.Reword" xml:space="preserve">编辑提交信息</x:String>
   <x:String x:Key="Text.CommitCM.SaveAsPatch" xml:space="preserve">另存为补丁 ...</x:String>
   <x:String x:Key="Text.CommitCM.Squash" xml:space="preserve">合并此提交到上一个提交</x:String>
-  <x:String x:Key="Text.CommitCM.SquashCommitsSinceThis" xml:space="preserve">合并之后的提交到 ${0}$</x:String>
   <x:String x:Key="Text.CommitDetail.Changes" xml:space="preserve">变更对比</x:String>
   <x:String x:Key="Text.CommitDetail.Changes.Count" xml:space="preserve">个文件发生变更</x:String>
   <x:String x:Key="Text.CommitDetail.Changes.Search" xml:space="preserve">查找变更...</x:String>

src/Resources/Locales/zh_TW.axaml

@@ -147,7 +147,6 @@
   <x:String x:Key="Text.CommitCM.Reword" xml:space="preserve">編輯提交訊息</x:String>
   <x:String x:Key="Text.CommitCM.SaveAsPatch" xml:space="preserve">另存為修補檔 (patch)...</x:String>
   <x:String x:Key="Text.CommitCM.Squash" xml:space="preserve">合併此提交到上一個提交</x:String>
-  <x:String x:Key="Text.CommitCM.SquashCommitsSinceThis" xml:space="preserve">合併之後的提交至 ${0}$</x:String>
   <x:String x:Key="Text.CommitDetail.Changes" xml:space="preserve">變更對比</x:String>
   <x:String x:Key="Text.CommitDetail.Changes.Count" xml:space="preserve">個檔案已變更</x:String>
   <x:String x:Key="Text.CommitDetail.Changes.Search" xml:space="preserve">搜尋變更...</x:String>

src/ViewModels/Histories.cs

@@ -497,21 +497,6 @@ public ContextMenu CreateContextMenuForSelectedCommits(List<Models.Commit> selec
                         e.Handled = true;
                     };
                     menu.Items.Add(reset);
-
-                    if (commit.IsMerged)
-                    {
-                        var squash = new MenuItem();
-                        squash.Header = App.Text("CommitCM.SquashCommitsSinceThis", commit.SHA.Substring(0, 10));
-                        squash.Icon = App.CreateMenuIcon("Icons.SquashIntoParent");
-                        squash.Click += (_, e) =>
-                        {
-                            if (_repo.CanCreatePopup())
-                                _repo.ShowPopup(new Squash(_repo, commit, commit.SHA));
-
-                            e.Handled = true;
-                        };
-                        menu.Items.Add(squash);
-                    }
                 }
                 else
                 {