Small friends fixes (#4270)

* Ensure that fetch errors are properly propagated

* Handle user not found errors better in add_friend

* Cargo fmt

* Introduce new LabrinthError returnable by fetch_advanced

* Allow enter key to send a friend request

packages/app-lib/src/error.rs

@@ -3,8 +3,17 @@ use std::sync::Arc;
 
 use crate::{profile, util};
 use data_url::DataUrlError;
+use derive_more::Display;
+use serde::{Deserialize, Serialize};
 use tracing_error::InstrumentError;
 
+#[derive(Serialize, Deserialize, Debug, Display)]
+#[display("{description}")]
+pub struct LabrinthError {
+    pub error: String,
+    pub description: String,
+}
+
 #[derive(thiserror::Error, Debug)]
 pub enum ErrorKind {
     #[error("Filesystem error: {0}")]
@@ -56,6 +65,9 @@ pub enum ErrorKind {
     #[error("Error fetching URL: {0}")]
     FetchError(#[from] reqwest::Error),
 
+    #[error("{0}")]
+    LabrinthError(LabrinthError),
+
     #[error("Websocket error: {0}")]
     WSError(#[from] async_tungstenite::tungstenite::Error),