Wrap STARTWIZARD_PAGE content in a wxScrolledWindow so pages can scroll
vertically on small or low-resolution screens. Clamp the wizard page
height to the available display client area minus space for chrome and
the button row so the Back/Next/Cancel buttons are always reachable.
Fixes https://gitlab.com/kicad/code/kicad/-/issues/23109
When the user imported settings from a previous version during the
startup wizard, the settings provider's Finish() reloaded all settings
from the migrated files. This changed the in-memory state so
data_collection_prompt became true (from the old version). The Finish
loop then re-evaluated NeedsUserInput() for each provider, causing
the privacy provider to be skipped
Fix this by tracking which providers had their wizard pages shown
using a flag
Fixes https://gitlab.com/kicad/code/kicad/-/issues/23051
Seth Hillbrand