garbage-collection package

This package should delete all links recursively using async handlers.

We create a `DeepDelete` link that goes from and to the deleted link. On HandleInsert we delete the selected links, that were using this link as `from`, `type` or `to`. This handler removes the `DeepDelete` link itself at the end of execution.

We also create a `CollectGarbage` node-link, that will enforce deletion of all standalone or broken links that have no connection to any contain tree.

10000 ₽ can be claimed as a reward. Reward will be paid to the first programmer that will make an NPM package that will pass review of @Konard