replace codespan-reporting with miette 3.0

crates/nu-protocol/src/span.rs

@@ -1,9 +1,17 @@
+use miette::SourceSpan;
+
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub struct Span {
     pub start: usize,
     pub end: usize,
 }
 
+impl From<Span> for SourceSpan {
+    fn from(s: Span) -> Self {
+        Self::new(s.start.into(), (s.end - s.start).into())
+    }
+}
+
 impl Span {
     pub fn new(start: usize, end: usize) -> Span {
         Span { start, end }