Create a simple dialogue authoring system, tied into our items (#10)

- Editor dialogue graph
- Asset importer for processing the graph into runtime data
- DialogueComponent that steers the dialogue interactions
- DialogueCanbas with a scalable speech bubble to display everything
- Brief README overview of the system

Co-authored-by: AlexanderT <alexander@foolhardyhorizons.com>
Co-authored-by: Michal Pikulski <michal.a.pikulski@gmail.com>
Reviewed-on: #10

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