👌 IMPROVE: Clean up top-level UI

I have some changes I would suggest to the top level UI:

* Remove the "Steps" buttons. You can just click on the tabs now, so I assume these are still here for some legacy reason?
* To make sure users can still start new workflows (and make this somewhat more intuitive), I'd add a nice big `button_style` "info" button to the line that contains the dropdown to select the workflow. The line should become:

Select workflow: [DROPDOWN] [REFRESH_BUTTON] [ Start new worfklow! ]
* Would be great it the dropdown text where you select your workflow would use a monospace font, but not sure if that's possible? I'd maybe also reformat it a bit, e.g.:

PK = {wc.pk} {some nice spacing} - {structure formula} {state} {last adjusted time}

I actually tried doing this, but got frustrated looking for how to change the font for the `DropDown`.

So then below this line you would just have the Step tabs. One additional feature that would be _super_ nice for using this in a real production environment is adding filters to the work chains you have in the dropdown. I think this already works by querying, so this should be reasonable easy to do. I'd add filters for:

* Structure formula elements, maybe separated with a dash? `-`
* State. Or just a checkbox with "Finished"
* Last adjusted time.

Since we don't want to overwhelm new users, we should hide this UI and have either a "Apply filter" button that then shows it, or maybe a dropdown tab or something.