feat: impl StackError for Arc<T: StackError> (#15)

## Description

Adds an impl for `StackError` for `Arc<T: StackError + std::error::Error>`. Makes it easy to to cloneable errors.

Author: Frando

src/error.rs

@@ -1,4 +1,7 @@
-use std::fmt::{self, Formatter};
+use std::{
+    fmt::{self, Formatter},
+    sync::Arc,
+};
 
 use crate::{AnyError, Location, Meta, backtrace_enabled};
 
@@ -353,3 +356,33 @@ impl_stack_error_for_std_error!(std::str::Utf8Error);
 impl_stack_error_for_std_error!(std::string::FromUtf8Error);
 impl_stack_error_for_std_error!(std::net::AddrParseError);
 impl_stack_error_for_std_error!(std::array::TryFromSliceError);
+
+impl<T: StackError + std::error::Error + Sized + 'static> StackError for Arc<T> {
+    fn as_std(&self) -> &(dyn std::error::Error + Send + Sync + 'static) {
+        (**self).as_std()
+    }
+
+    fn into_std(self: Box<Self>) -> Box<dyn std::error::Error + Send + Sync> {
+        self
+    }
+
+    fn as_dyn(&self) -> &dyn StackError {
+        (**self).as_dyn()
+    }
+
+    fn meta(&self) -> Option<&Meta> {
+        (**self).meta()
+    }
+
+    fn source(&self) -> Option<ErrorRef<'_>> {
+        StackError::source(&**self)
+    }
+
+    fn fmt_message(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        (**self).fmt_message(f)
+    }
+
+    fn is_transparent(&self) -> bool {
+        (**self).is_transparent()
+    }
+}