feat: add toArray() method to Progressable trait

[insign]

Adds a toArray() method to the Progressable trait to export the current state (progress, steps, eta, status message, metadata) easily. This allows developers to serialize and retrieve the entire progress state efficiently. Added comprehensive PHPUnit tests to cover both scenarios with and without a unique name.

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PR created automatically by Jules for task 1909096901814996662 started by @insign

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