fdo#70198: sw: don't truncate Time values on 32bit platforms

SwDoc::SetFixFields() uses sal_uLong to store Time.GetTime() which needs
64 bits.

Also fix same problem on Time fields in HTML import.

(regression from 9830fd36dbdb72c79703b0c61efc027fba793c5a)

(cherry picked from commit 17dab5bf8efb3fd676e6854474b199b681d0dc28)

Conflicts:
	sw/source/filter/html/htmlfld.cxx

Change-Id: I5d0388cbc364e1f9dfb60ff9e83c7d2f101c69d8
Reviewed-on: https://gerrit.libreoffice.org/7020
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>