erp5_post: Sort the post list when fetching the content from database. And only get the post which state is "published".

The comment user field in the listbox which list Support Requests should show
the latest person who left comment.

Allowed change cache to update application.

The keys in the `count_by_state` dict in SupportRequest_getSupportRequestStatisticsAsJson.py
was hardcoded in previous version. This commit can add the keys to the dict dynamically according
to the states of Support Request. Thus the code can still work if there has new state added to
Support Request.

Users may upload PDF files when they submit comment under a support request.
This commit allow user to view the PDF file after they upload it.

The 'form_view_discussable' allow user to visit the 'OfficeJS View' in classic ERP5 interface.
This was copied from 'form_view' and the 'discussable' part is not implemented in this page template.

In the case the CTP is for a refund