This moves the property of brushes and filter operator to enable
collisions in the sculpt cloth solver to the sculpt settings. This way,
the same property is shared between all uses of the solver (brushes,
filters and deformation targets). This makes sense as this is a prefernce
of the solver, not something that defines the behaviour of a tool.

After this patch I'll start adding more solver options (iterations,
deformation constraints strength...) to the same place in the UI, that
will also affect all tools that use the solver.