* add `Shift+Ctrl+Tab` (`⌘+⌥+←` on macOS) to go to previous page
* use `ESC` to cancel commit searching
* enable `AutoFocusBehaviour` on `CommitChanges` and `RevisionFiles` tab
* remove dotnet-tool.json because the project does not rely on any dotnet tools.
* remove Directory.Build.props because the solution has only one project.
* move src/SourceGit to src. It's not needed to put all sources into a subfolder of src since there's only one project.