Split conflicts into their own section (#24324)

Co-Authored-By: Mikayla <mikayla@zed.dev>

Release Notes:

- N/A

crates/git/src/repository.rs

@@ -46,6 +46,8 @@ pub trait GitRepository: Send + Sync {
     /// Returns the SHA of the current HEAD.
     fn head_sha(&self) -> Option<String>;
 
+    fn merge_head_shas(&self) -> Vec<String>;
+
     /// Returns the list of git statuses, sorted by path
     fn status(&self, path_prefixes: &[RepoPath]) -> Result<GitStatus>;
 
@@ -162,6 +164,18 @@ impl GitRepository for RealGitRepository {
         Some(self.repository.lock().head().ok()?.target()?.to_string())
     }
 
+    fn merge_head_shas(&self) -> Vec<String> {
+        let mut shas = Vec::default();
+        self.repository
+            .lock()
+            .mergehead_foreach(|oid| {
+                shas.push(oid.to_string());
+                true
+            })
+            .ok();
+        shas
+    }
+
     fn status(&self, path_prefixes: &[RepoPath]) -> Result<GitStatus> {
         let working_directory = self
             .repository
@@ -387,6 +401,10 @@ impl GitRepository for FakeGitRepository {
         None
     }
 
+    fn merge_head_shas(&self) -> Vec<String> {
+        vec![]
+    }
+
     fn dot_git_dir(&self) -> PathBuf {
         let state = self.state.lock();
         state.dot_git_dir.clone()