Rename SharedUrl to SharedUri (#7084)

This PR renames `SharedUrl` to `SharedUri` to better reflect its intent.

I'm still not entirely happy with this naming, as the file paths that we
can store in here are not _really_ URIs, as they are lacking a protocol.

I want to explore changing `SharedUri` / `SharedUrl` back to alway
storing a URL and treat local filepaths differently, as it seems we're
conflating two different concerns under the same umbrella, at the
moment.

Release Notes:

- N/A

crates/gpui/src/shared_uri.rs

@@ -0,0 +1,65 @@
+use std::ops::{Deref, DerefMut};
+
+use crate::SharedString;
+
+/// A URI stored in a [`SharedString`].
+#[derive(PartialEq, Eq, Hash, Clone)]
+pub enum SharedUri {
+    /// A path to a local file.
+    File(SharedString),
+    /// A URL to a remote resource.
+    Network(SharedString),
+}
+
+impl SharedUri {
+    /// Creates a [`SharedUri`] pointing to a local file.
+    pub fn file<S: Into<SharedString>>(s: S) -> Self {
+        Self::File(s.into())
+    }
+
+    /// Creates a [`SharedUri`] pointing to a remote resource.
+    pub fn network<S: Into<SharedString>>(s: S) -> Self {
+        Self::Network(s.into())
+    }
+}
+
+impl Default for SharedUri {
+    fn default() -> Self {
+        Self::Network(SharedString::default())
+    }
+}
+
+impl Deref for SharedUri {
+    type Target = SharedString;
+
+    fn deref(&self) -> &Self::Target {
+        match self {
+            Self::File(s) => s,
+            Self::Network(s) => s,
+        }
+    }
+}
+
+impl DerefMut for SharedUri {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        match self {
+            Self::File(s) => s,
+            Self::Network(s) => s,
+        }
+    }
+}
+
+impl std::fmt::Debug for SharedUri {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::File(s) => write!(f, "File({:?})", s),
+            Self::Network(s) => write!(f, "Network({:?})", s),
+        }
+    }
+}
+
+impl std::fmt::Display for SharedUri {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.as_ref())
+    }
+}