[WIP] Delete all records matching a query

Sorry, I'm having a bit of trouble digging through the code.

I think that this basic structure is correct for adding this functionality, but I'm unsure what to write in the `update_delete_all` method. Should it update some flag in the `request_options` `hash_storage`?

After that, where is the code that actually sends the request to ES? Will need to have it check for the new delete flag and send a DELETE request if it is true.
This method, however, does not work. It can't find the `delete_all` method. I tried to follow what you wrote in the issue, but probably messed up somewhere. I'm pretty unfamiliar with Ruby, how should this be structured differently so it can find the method?

Here is what you wrote in the issue:
```ruby
def Chewy::Type::Base.reset
  delete_all
  import
end
```