[FEATURE] - Remove `ScrollbarWithCustomPhysics` usage from `SuperEditor`

[angelosilvestre]

In #1649, we introduced ScrollbarWithCustomPhysics, to allow the use of a custom ScrollPhysics because, at the time, we handled the scrolling ourselves.

We don't need to use ScrollbarWithCustomPhysics in SuperEditor anymore, because we no longer handle scrolling manually.

Remove its usage from SuperEditor. However, we still need it in SuperTextField yet.