Implement `NoCell`, `IntoBytes` and possibly other traits for `std::convert::Infallible`

**What is the name of your project?**
Fuchsia netstack3

**Please provide a link to your project (GitHub repository, crates.io page, etc).**
https://cs.opensource.google/fuchsia/fuchsia/+/main:src/connectivity/

**What features would you like from zerocopy?**
It might be useful to implement `NoCell`, `IntoBytes` and possibly other traits for `std::convert::Infallible` so that it can be used e.g. in associated types. This would improve how specific invariants are enforced and would allow use `Infallible` instead of `()` or a custom defined type with the same behavior of `Infallible`.