Bug 10523: Remove two obsolete routines from Installer.pm

Bug 10523: Remove two obsolete routines from Installer.pm

The routines sql_file_list and marcflavour_list in Installer.pm are not used.
There are some references to them in probably obsolete '/lib' test units.
I changed these test units for the record too.

Also: removed the not-existing marcflavour parameter of sample_data_sql_list
in its call in install.pl.

Test plan:
Run a new install.

Signed-off-by: Paola Rossi <paola.rossi@cineca.it>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>