CreateMany in the Payload local API

[MarkAtOmniux]

I've come across a few situations where I have had to add multiple documents at once and done so using the local API and Promise.all() to resolve them asynchronously. Though this is faster than running in sync, it is nothing in comparison to a batch DB operation.

It is currently possible to perform bulk operations using the underlying DB wrapper, but I feel that this detracts from the DevX of Payload. So my proposal is to add the ability to perform bulk Add documents using the local API.

This feature will allow developers to perform bulk actions much quicker, rely less on the DB layer, and also allow us to keep a lot of the convenience features baked into the local API such as access control and the context object.