Filter on task state for Worker Explorers

[lissyx]

Analyzing the status of current workers, especially those on aws-provisioner, it's hard to get information, because of the X-elements per page limitation. Being able to filter on the task state, e.g., "running" would allow me to easily track the status.

[helfi92]

The list of workers used in that page are stored in Azure and it's currently hard to filter on a task state because the response is paged. We plan on storing the data in Postgres in the near future, hopefully making things easier to filter on.