Existing code with endnotes on separate page at the end of the document
works by searching for a current or next page that is an endnote page in
SwFootnoteBossFrame::AppendFootnote(), and in case none is found, then
an endnote page is created.
Add similar infrastructure for the inline endnotes case: here we want to
find the first page that has an endnotes section, which also requires
being able to tell if a section is an endnotes one.
The newly introduced SwPageFrame::GetEndNoteSection() is not yet used in
SwFootnoteBossFrame::AppendFootnote(), though.
Change-Id: Ib08267f9bf6c7b06576624e3fa8e90e8b8b1b232
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/167371
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins