Add EntityRef::get_components_dyn() and EntityMut::get_components_dyn() to query multiple components #15577
Description
What problem does this solve or what need does it fill?
The dynamic query API World::get_many_entities_dynamic_mut() returns an EntityMut which can access all components of an entity... but only one by one. Often you need to access 2+ components at once.
What solution would you like?
Add the proposed methods which allow retrieving more than 1 component at once.
What alternative(s) have you considered?
There's no alternative possible from user code I think.