[10pt, 10pt]Restructure layout computations to make rendered output more consistent

[wirew0rm]

Goals:

• ensure chart is always self-consistent after a rendering pass
  • having a single frame with e.g. some clipping is acceptable for a frame, if otherwise we would have to make very pessimistic assumptions which would be bad for performance, but all chart elements (labels, grid, plots) should be at consistent positions in every frame.
• reduce the levels of scene graph hierarchy of the Chart component
• ideally this will solve or make the solution a lot simpler for these issues: #474, #410, #204
• improve integration with JavaFx properties and CSS styling facilities

Items to be investigated implemented:

• Separate range computations, layout calculations and actual graphics context rendering in the layout phase by
  • either calling different functions in the layoutChildren implementation of Chart
  • or using the pre-/post-render hooks of javafx
• Reimplement Chart as a layout container which explicitly implements a custom layout Children
  • preiminary investigation/implementation in #529 and the corresponding newLayout branch
• implement global locking of datasets per render pass
  • currently range computation and rendering separately lock the dataset which is not safe and requires multiple checks
• have a dataset node type to hold things like dirty bit, bindable properties, etc
  • datasets can update stylable properties of the wrapper via their style (or add style classes)
  • investigate relationship of this new wrapper to DataSetManagement (base class of renderer)
  • chart (and renderers?) store List, helper functions to get or remove raw DataSet
  • DataSetNode can be in scenegraph once, but Multiple DataSetNodes can refer to the same DataSet
  • DataSetNode is only handled in FxThread, DataSet is thread safe by default
• have a simple way to disable multithreading in the DataSet
  • should default to safe/locked implementation

[ennerf]

As per discussion on June 21 with Alex and updated July 21.

Deterministic layout and hierarchy changes

• [x] Split layout and rendering
• [x] Perform layout based on properties in the children nodes
• [x] Report consistent axes size and do the axis layout in a deterministic way
• [x] Simplify chart hierarchy levels

Smaller changes that would be better in a separate PR.

• [x] Remove XYChart class and use Chart directly
• [x] Remove dataset list from main chart and keep datasets within the renderer. The global color index should be maintained.
• [x] Deprecate delegating methods, e.g., chart delegating to the grid renderer
• [x] Change renderer to always have one X and one Y axis. If one is not defined it defaults to the first one.

[ennerf]

I think the goals have all been achieved and are ready for review. The style nodes ended up not being necessary.

[ennerf]

Below are some before and after pictures

Before	After	Comment
		The chart anatomy parts can still be fully accessed, but without the need for StackPane wrappers
		All of the extra layout panes were removed and have been replaced with a small hierarchy of custom panes. Axis layouts are now deterministic and can be done without recursion.
		labels don't disapper when resizing
		tick label spacing is now computed correctly
		disabled ranges now correctly remove the invalid tick labels (bottom left)
		enabling an axis does not break the label positioning anymore
		all rotations and overlap strategies get correctly rendered

Most importantly, the data rendered on the chart is now always consistent with the value shown on the axes.

Here is a video of one of our applications that used to have significant rendering issues: Deterministic Layout PR