Move git state to Project (#23208)

This restores its visibility outside of git_ui, which we'll need soon,
while preserving its per-project character.

Release Notes:

- N/A

crates/worktree/src/worktree.rs

@@ -2583,6 +2583,17 @@ impl Snapshot {
         &self.repositories
     }
 
+    pub fn repositories_with_abs_paths(
+        &self,
+    ) -> impl '_ + Iterator<Item = (&RepositoryEntry, PathBuf)> {
+        let base = self.abs_path();
+        self.repositories.iter().map(|repo| {
+            let path = repo.work_directory.location_in_repo.as_deref();
+            let path = path.unwrap_or(repo.work_directory.as_ref());
+            (repo, base.join(path))
+        })
+    }
+
     /// Get the repository whose work directory corresponds to the given path.
     pub(crate) fn repository(&self, work_directory: PathKey) -> Option<RepositoryEntry> {
         self.repositories.get(&work_directory, &()).cloned()