Filtering by worker

[amleaver]

Using an approach similar to #149 would there be any appetite for adding the ability to filter jobs by worker? I was thinking something simple wherein a user can enter a worker name as a freeform string and it'd match any workers containing the string.

I'm happy to put together a PR, assuming there's no reason this functionality shouldn't exist.

With regards to the UI perhaps something like the following would suffice:

I'm happy for other suggestions, as personally I'm not a massive fan of how much horizontal space this new form field would need compared to the status and pagination dropdowns that are already supported.