Convert Sysprof surface to IdePage
As we move towards GTK 4, we want to rethink our IdeSurface abstraction. It isn't really used much and even if we keep it as an abstraction, we probably need to rethink how Sysprof integrates.
As a side note, IdeSurface can probably become IdeWorkspaceChild since it is a child view for a workspace and is less confusing given that GDK now has GdkSurface.
One thought is that instead of the Sysprof surface we can make a Sysprof IdePage and open them in views. That probably fits more naturally to how sysprof evolved anyway.