MdeModulePkg/FileExplorer: Update QuesrionId when Updating FileExplore form

MdeModulePkg/FileExplorer: Update QuesrionId when Updating FileExplore form

https://bugzilla.tianocore.org/show_bug.cgi?id=342

When user select and enter a directory, File Explorer will update the
form based on the new folders and files in the directory. But when
creating question opcodes, the question id is same with previous one
and this will cause browser to show the highlight menu incorrectly.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Dandan Bi <dandan.bi@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>