GroupTreePlot/FlowNetwork refactoring and new features

[jorgenherje]

FlowNetwork-module uses the GroupTreePlot-component from webviz-subsurface-components.

Refactoring of GroupTreePlotcomponent is needed for improved functionality and structure.

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General issues and considerations:

• Consider new component/package vs refactoring of old
• Move from JavaScript to TypeScript implementation - #714
  • Main focus on GroupTreeAssembler
• Ensure component to utilize available space/height - #715
  • Should follow resizing of window without too heavy re-rendering.
  • Now hardcoded to 700px: this._rectHeight
• Support having initially collapsed view (collapse/hide children nodes and branches) - #713
• Click on node does not always collapse/expand children - #712
• Show rate number on hover and unit of value in nodes - #716