Jolt physics: wake up a soft body when its transform changes
This updates `JoltSoftBody3D::set_transform()` to wake up the
soft body after changing the transform.
Previously, if you had a soft body that was sleeping in a steady state
on a ground plane, and you then translated it upwards by 1 meter it
would just hang in the air. Now it falls to the ground correctly.
Issue #108090 has some details and an MRP (although that issue is mostly
about other problems in SoftBody3D iteself).