None filter

[Kestrer]

In chains of ors, it can look nice to have all the branches look equal. For example:

route_1
    .or(route_2)
    .or(route_3)

This doesn't look nice as the first route is at a different indentation level to all the other routes, and isn't surrounded by brackets.

If a none/no filter was added to Warp (opposite of any), the above could be written as:

warp::none()
    .or(route_1)
    .or(route_2)
    .or(route_3)

Which allows the code to look cleaner and more consistent.