Bug 16371: Move GetDailyQuote to get_daily_quote

Bug 16371: Move GetDailyQuote to get_daily_quote

This patch moves subroutine 'GetDailyQuote' to new
Koha::Quote object and adjusts tests.

To test:
1. Set 'QuoteOfTheDay' as 'enable'
2. Check that quote is displayed on OPAC mainpage

Prove t/db_dependent/Koha/GetDailyQuote.t

Sponsored-by: Koha-Suomi Oy
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>