Add the initial form step field to the multi-step form block

[ConorWebb96]

Describe the feature request
Add the initial form step field to the multi-step form block, currently you can't change the current step of the form dynamically. You have to eject and configure it on the form itself if you want to do something along these lines at the moment.

Screenshots
Multi-step form block settings

Ejected form setting for setting the initial step

[linear]

BUDI-8254 Add the initial form step field to the multi-step form block