Bug 36777: Add new section for lost item circulation preferences

Bug 36777: Add new section for lost item circulation preferences

This moves lost item circulation system preferences from
'Checkout policy' to their own 'Lost item policy' section.

It also fixes a capitalization issue - 'Fines Policy' to
'Fines policy'.

Test plan:
1. View the circulation system preferences page (Administration >
   System preferences > Circulation).
2. Search the page, and note that there are several system
   preferences about lost items in the 'Checkout policy' section.
3. Apply the patch.
4. Refresh the page.
5. Note that there is now a new section heading 'Lost item policy'.
   The system preferences previously under 'Checkout policy' are
   now located in this new section.
6. Sign off D:

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Tadeusz „tadzik” Sośnierz <tadeusz@sosnierz.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>