Flow graph initial iteration

[carolhmj]

This is the initial work for an engine that will support a paradigm of creating chains of actions that trigger in response to events (a "flow graph"). Please note it is still experimental and subject to many changes until its final iteration.

Example PG: #P0U4WL#2 (Click on the mesh and it will run a for loop from 0 to 10 (exclusive) and print its index + 1)
#P0U4WL#1 (Click on the mesh and it will print its name)

EDIT: updated the example PG with the most recent syntax

[bjsplat]

Please make sure to label your PR with "bug", "new feature" or "breaking change" label(s).
To prevent this PR from going to the changelog marked it with the "skip changelog" label.

[bjsplat]

Please make sure to label your PR with "bug", "new feature" or "breaking change" label(s).
To prevent this PR from going to the changelog marked it with the "skip changelog" label.

[bjsplat]

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[RaananW]

Before submitting my review - this PR is missing code doc (ts doc for functions/classes), which would help provide scope to each component

[bjsplat]

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[bjsplat]

Visualization tests for webgl2 have failed. If some tests failed because the snapshots do not match, the report can be found at

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[RaananW]

General comment - dispose should be implemented wherever it makes sense (removing observers, removing event listeners (if used) etc'.

[Popov72]

The framework seems quite easy to use!

I think we need some examples to better understand how it all fits together.

[RaananW]

just a small comment :-)

[RaananW]

@Popov72 - just waiting for your final approval