implement errors handler

src/gio/network_address/error.rs

@@ -0,0 +1,16 @@
+use std::fmt::{Display, Formatter, Result};
+
+#[derive(Debug)]
+pub enum Error {
+    Host(String),
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        match self {
+            Self::Host(url) => {
+                write!(f, "Host required for {url}")
+            }
+        }
+    }
+}