Design a easy to use API and data representation for actions.

[Dandielo]

Currently you need to create actions using the very verbose and data oriented API.
The creation is sub-par and there is not a single way to save and load actions later on.

A few things that should be considered:

• What type of actions are the most common ones?
• How do we want to create actions in code? Some kind of builder?
• How should we represent multiple actions and exchange actions on the fly?
• Should we provide utility for action triggers, like button clicks?

Design task to finish

• Answer the above questions.
• Implement a prototype for the answers.
• Prepare a common actions asset, for player movement.
• Update the test app.

[Dandielo]

This is a follow-up ticket of #69