[gSender PR#239] Wizard Improvements

– prevent other actions from being taken until current running action is complete
– feederCB used to run step finished code once gcode is finished running
– when gcode is being run, buttons are replaced with dynamic “Running…” text to show user that something is being run on the backend
– fixed flow of wizard
– completeStep and completeSubStep variables now added to keep track of completed steps
– completed steps are whatever steps the user has finished running code for/have pressed continue on
– if the user has finished a step, it will stay marked as completed, even if they press back
– active step exists to show the current highlighted step. wizard auto scrolls to this step
– back button decrements active step only
– continue button marks the newly completed step and moves the active state up
– fixed some stylint errors