feat(worktree): add base bindings and api

lib/src/worktree.dart

@@ -0,0 +1,54 @@
+import 'dart:ffi';
+import 'bindings/libgit2_bindings.dart';
+import 'bindings/worktree.dart' as bindings;
+import 'repository.dart';
+
+class Worktree {
+  /// Initializes a new instance of [Worktree] class by creating new worktree
+  /// with provided [Repository] object worktree [name] and [path].
+  ///
+  /// Should be freed with `free()` to release allocated memory.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  Worktree.create({
+    required Repository repo,
+    required String name,
+    required String path,
+  }) {
+    _worktreePointer = bindings.create(repo.pointer, name, path);
+  }
+
+  /// Initializes a new instance of [Worktree] class by looking up existing worktree
+  /// with provided [Repository] object and worktree [name].
+  ///
+  /// Should be freed with `free()` to release allocated memory.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  Worktree.lookup(Repository repo, String name) {
+    _worktreePointer = bindings.lookup(repo.pointer, name);
+  }
+
+  /// Pointer to memory address for allocated branch object.
+  late final Pointer<git_worktree> _worktreePointer;
+
+  /// Returns list of names of linked working trees.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  static List<String> list(Repository repo) => bindings.list(repo.pointer);
+
+  /// Returns the name of the worktree.
+  String get name => bindings.name(_worktreePointer);
+
+  /// Returns the filesystem path for the worktree.
+  String get path => bindings.path(_worktreePointer);
+
+  /// Prunes working tree.
+  ///
+  /// Prune the working tree, that is remove the git data structures on disk.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  void prune() => bindings.prune(_worktreePointer);
+
+  /// Releases memory allocated for worktree object.
+  void free() => bindings.free(_worktreePointer);
+}