fix: set projectId in jobs emitted by load streams

[1kilobit]

This explicitly sets the project ID in jobs returned by loading operations that are stream-based (e.g. Table.load(filePath) or Table.createWriteStream()), which fixes support for project IDs specified at the dataset level.

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Fixes #1345 🦕

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[alvarowolfx]

Thanks for the contribution @onekilobit-supersocial. Changes looks good to me. I'll wait for CI test to run and merge it.