Escape work pool names when translating from CLI/UI to API URLs

[chrisguidry]

We had an instance of a customer with a work pool named ' some-word\' which couldn't be removed via the UI or the API due to the leading space and the trailing \. Work pools are a little different from many of our domain objects, as they are referenced in URLs by their names, and that's the only way to DELETE them at the moment.

When the CLI or UI translate work pool names into API URLs, they should each be using HTTP URL encoding, so that example above would become '%20some-word%5C' when used in URLs.