impl Serialize for Mxc using Display/to_string() for now

Signed-off-by: Jason Volk <jason@zemos.net>

crates/ruma-common/src/identifiers/mxc_uri.rs

@@ -6,6 +6,7 @@ use std::{fmt, num::NonZeroU8};
 
 use ruma_identifiers_validation::{error::MxcUriError, mxc_uri::validate};
 use ruma_macros::IdZst;
+use serde::{Serialize, Serializer};
 
 use super::ServerName;
 
@@ -98,6 +99,12 @@ impl<'a> TryFrom<&'a OwnedMxcUri> for Mxc<'a> {
     }
 }
 
+impl Serialize for Mxc<'_> {
+    fn serialize<S: Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
+        s.serialize_str(self.to_string().as_str())
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use ruma_identifiers_validation::error::MxcUriError;