Reconsider deprecation of disable-multi-item-change

[1valdis]

The deprecation notice suggests usage of multi: true option, but the problem is multi: true has no flexibility at all and sets the behavior for both internal and external calls (see feathersjs/feathers#2546), while the disableMultiItemChange hook be used conditionally, for example iff(isProvider('external'), disableMultiItemChange()). Due to its flexibility, I think its deprecation should be reconsidered and it could be included back to feathers-hooks-common.