Cleanup interrupt package naming. Fixes #40

The `interrupt` package previously tried to be drop-in compatible with the
`interrupt` package from PACs. THis meant that there was both a PAC-style enum
value `UARTE0` and an embassy-style owned `UARTE0Interrupt` type. This made
things VERY confusing.

This drops compatibility with the PAC, improving the names for embassy interrupts.

embassy-nrf/src/util/peripheral.rs

@@ -4,10 +4,10 @@ use core::pin::Pin;
 use core::sync::atomic::{compiler_fence, Ordering};
 
 use crate::fmt::*;
-use crate::interrupt::OwnedInterrupt;
+use crate::interrupt::Interrupt;
 
 pub trait PeripheralState {
-    type Interrupt: OwnedInterrupt;
+    type Interrupt: Interrupt;
     fn on_interrupt(&mut self);
 }