Yfiles-jupyter-graphs-for-neo4j

New Features
* The `parent_configuration` mapping now supports lambdas with the node as first parameter
* Support a configurable node-to-cell mapping (`widget.node_cell_mapping`) that is considered by the automatic layout algorithms such that nodes are placed in the given grid cell. Typical use cases may be to highlight a critical path structurally by aligning these nodes in a row/column. For example, see [this yFiles Graphs for Jupyter notebook](https://github.com/yWorks/yfiles-jupyter-graphs/blob/main/examples/feature-releases/v1.9.ipynb).
* Added `circular_straight_line` as new layout option that creates a circular layout with straight connections, instead of the bundled connections of the existing `circular` layout.
Improvements
* Adjusted the interactive organic layout settings to make the result more airy.
Bugfixes
* Fixed interactive organic failing when used multiple times in separate widgets in the same notebook.
* Fixed widget resizing issue after switching from map-view to the normal graph view.

* Allow specifying the layout for the resulting graph.

* Use the default sidebar behavior of `yfiles-jupyter-graphs` (i.e. the sidebar is initially collapsed if not specified otherwise).
* Use raw image URLs in `README` to show the images the PyPI registry homepage.

New grouping support

* The new `add_parent_relationship_configuration(type, reverse)` allows to restructure relationships as nested hierarchy. For example, `(n:Person)-[r:COUNTRY]->(m:Country)` relations can be visualized as persons that are nested within their respective country.
* The new `parent_configuration` keyword argument for the `add_node_configuration(label, **kwargs)` allows to create artificial group nodes that are not part of the database.

You can find more details and examples in the [grouping.ipynb](https://github.com/yWorks/yfiles-jupyter-graphs-for-neo4j/blob/main/examples/grouping.ipynb) notebook.

* Fixed the bug that caused shared configuration among different widget instances (see 6)

Remove obscure grouping sample

Add support for heat-mapping, geo-spatial mapping and parent mapping.