* feat: remove orphan remote-tracking branches
- Allow user remove local remote-tracking branches without remotes (ie. remote was removed on merge request).
- Included 'DeleteRemoteTracking' and 'HasRemote' util methods to handle this case.
* fix: delete both case (local & remote-tracking)
- We have local and remote-tracking but not a remote branch. We need to remove both or only the tracking based on the checkbox and on the 'hasRemote' condition
* 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.
