feat(vcs): mark the current worktree in the Worktrees list (#1506)

The worktree whose path is the window's repository root gets a check before its branch (Current worktree); drive paths compare case-insensitively. Branch names keep their width and the path is cut short instead.

src/platform/locales/text/zh.json

@@ -2707,6 +2707,7 @@
   "New Worktree…": "新建工作树…",
   "Worktrees…": "工作树…",
   "Worktrees": "工作树",
+  "Current worktree": "当前工作树",
   "New Worktree": "新建工作树",
   "Git Remotes": "Git 远程",
   "Define Remote": "定义远程",