Workaround: changed default layout mode.

- Bug: Nothing is displayed when graph contains only one vertex.
- Bug: Crash when using layouts like EfficientSugiyama and Tree when using 2 or less vertices.
Added on-screen notifications.
Added detailed error messages for ConfigurationEditor. (...)

- Fixed animation layout for notifications.
- Restored partial save/load functionality (excludes ConfigurationManager entirely).
MainWindow: Commenting the bottom panel out while logs aren't used.
Merge branch 'feature/lab-bugfixes' into develop