Features/get set value

[hybridherbst]

Various other fixes.

Here is a fun test file with a little calculator that works in the Graph Authoring Tool with the changes in this PR:

• https://github.com/BabylonJS/Babylon.js/pull/15810#issuecomment-2493834017

Changes:

• add math/clamp node
• fix initial values for variables
• added more types to ADBE log
• fixed variable set and get, was not using "value" as input/output id
• renamed "val" to "value"

[CLAassistant]

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