When opening "Add new workflow task" modal, put cursor in search box

[jluethi]

When I open this page to add a task to a workflow:

I'd like to be able to just start typing to search for a task of interest. Can we put the text input in the search field automatically, as if I had clicked on it? e.g. the box then looks like this

(no opinion on whether the box should or shouldn't be highlighted, either is fine by me. I just want the functionality to type right away ;) )

[jluethi]

That's great! Can we do the same for the main task page one gets to when clicking on "Tasks" in the header? The one that isn't shown as a modal.

[zonia3000]

Done in 0d0111c (PR #707)