Allow setting single components instead of single component tuples in query-based effects

[Trouv]

All query-based effects require using a component tuple as C being set directly or with some impl Fn(C) -> C. However, it's pretty common that users will only want to update one component, in which case users need to set (MyComponent,) directly or with some impl Fn((MyComponent,)) -> (MyComponent,). Needless to say, the tuplified type is a bit more cumbersome.

This issue is for implementing effect for these types when C is a plain component.