Handle cancelling/aborting while processing a turn (#5543)

Currently we collect all all turn items in a vector, then we add it to
the history on success. This result in losing those items on errors
including aborting `ctrl+c`.

This PR:
- Adds the ability for the tool call to handle cancellation
- bubble the turn items up to where we are recording this info

Admittedly, this logic is an ad-hoc logic that doesn't handle a lot of
error edge cases. The right thing to do is recording to the history on
the spot as `items`/`tool calls output` come. However, this isn't
possible because of having different `task_kind` that has different
`conversation_histories`. The `try_run_turn` has no idea what thread are
we using. We cannot also pass an `arc` to the `conversation_histories`
because it's a private element of `state`.

That's said, `abort` is the most common case and we should cover it
until we remove `task kind`

codex-rs/core/src/error.rs

@@ -1,3 +1,4 @@
+use crate::codex::ProcessedResponseItem;
 use crate::exec::ExecToolCallOutput;
 use crate::token_data::KnownPlan;
 use crate::token_data::PlanType;
@@ -53,8 +54,11 @@ pub enum SandboxErr {
 
 #[derive(Error, Debug)]
 pub enum CodexErr {
+    // todo(aibrahim): git rid of this error carrying the dangling artifacts
     #[error("turn aborted")]
-    TurnAborted,
+    TurnAborted {
+        dangling_artifacts: Vec<ProcessedResponseItem>,
+    },
 
     /// Returned by ResponsesClient when the SSE stream disconnects or errors out **after** the HTTP
     /// handshake has succeeded but **before** it finished emitting `response.completed`.
@@ -158,7 +162,9 @@ pub enum CodexErr {
 
 impl From<CancelErr> for CodexErr {
     fn from(_: CancelErr) -> Self {
-        CodexErr::TurnAborted
+        CodexErr::TurnAborted {
+            dangling_artifacts: Vec::new(),
+        }
     }
 }