Word navigation in QuickOpen

<!-- Please search existing issues to avoid creating duplicates. --> <!-- Also please test using the latest insiders build to make sure your issue has not already been fixed: https://code.visualstudio.com/insiders/ --> - VSCode Version:1.40.1 - OS Version:window10 Steps to Reproduce: 1.By going to file snapshot (CTRL +P),Type the word aaa:BBB:XXX in the open box 2.Then use the shortcut key CTRL + left or right head to move the cursor position 不合理现象:光标不能以冒号(:)为基本单位去移动位置 Unreasonable: the cursor cannot be moved with a colon (:) as the basic unit <!-- Launch with `code --disable-extensions` to check. --> Does this issue occur when all extensions are disabled?: Yes