[fix] queue consumption: catch throwable for processing errors

[macghriogair]

This fixes the issue with unhandled Errors described in #1113

tbd. if this might be considered breaking backward compatibility or if I missed any important place.
Actually it should not, since \Exception extends from \Throwable. But feel free to comment & object.

[makasim]

Thanks for your pull request! We love contributions.

However, this repository is what we call a "subtree split": a read-only copy of one directory of the main enqueue-dev repository. It is used by Composer to allow developers to depend on specific Enqueue package.

If you want to contribute, you should instead open a pull request on the main repository:

https://github.com/php-enqueue/enqueue-dev

Read the contribution guide

https://github.com/php-enqueue/enqueue-dev/blob/master/docs/contribution.md

Thank you for your contribution!

[macghriogair]

Ah, my bad! I'll change that.

[macghriogair]

Closing in favor of: php-enqueue/enqueue-dev#1114