Additional changes:
- Refactored Prefabs/UI/Facts project structure

The FactExplorer Window shows other facts that reference the selected facts and also shows facts referenced by the selected fact.

WorldFactInteraction:
Hovering over a worldspace fact in mathmode now shows the fact display. This display can be dragged into scrolls like facts from the fact display.

Additional changes:
- WorldFactInteraction added to Mathmode canvas, as it should only be active if the canvas is active
- Sorting order of Math canvas increased to 10 (from 0), so that dragged facts will always be displayed on top
- DisplayFacts Dictionary is now static and thus available from other classes that need the fact display (this is not ideal and should maybe be extracted)
- DragHandling: dragged variable now public, as this is of interest to other classes

Removed unnecessary debug statements.

+New Polymorphismus for JSON serialization for Solution-/FactOrganizer and Fact; +added using keyword for UnityWebRequest

Suggested by unity warnings
Old version worked as well

Changed EventHandling to OnPointerDown as otherwise scroll events were not passed through
Changed Scrollscreen layout to GridLayout under new 'Scrolls' Gameobject
Improved Scrollscreen layout

Fact display now also does not cover up the scroll area anymore (mask)
Dragged facts get moved to bottom of canvas hierachy while being dragged, so they are visible above all other ui

+Doygen for most of Assets/Scripts/InteractionEngine/FactHandling/* and Gadget.cs +Bug fixes for saving/loading fuctionalities of Stages

+MainMenue: Create new Stage files via UI +StageStatic: differentiate between developing and playing

+Added Scenes: MainMenue, LoadingScreen +Stage: Save-Load fuctionality +Sorted Prefabs and Scripts Folder

+FactOrganizer: hid FactDict +Facts: re-renamed URI to Id, enabled persistend, generated and compact LabelNamingSpace

+Restart: reenabled RestartLevelButton +Level: reenabled Level-completion +FactOrganizer: scetch for dynamic LevelGoals, with-> +FactComparer +ShinyThings: TODO: multiple highlited facts at once

+added Lot&Pendulum-Tool +Using Math3d lib for VectorCalculus +Changed Fact managment (unstable\!) +Misc refactoring

Added the possibility to enable/disable the features DynamicScrollDescriptions and AutomaticHintGeneration

Fixed json-payload for OnLineFacts and LineFacts + Adjustments so that SupplementaryAngles-Scroll works again + Adjusted GET on Scroll/List-endpoint in DisplayScrolls so that it tries several times, because server mostly returns a 500 on first try