Bug 5859: Allow user to set encoding for import

Bug 5859: Allow user to set encoding for import

Rather than having options for MARC21 and UNIMARC in the "Character encoding"
dropdown, the user should be able to select the appropriate character encoding.
The default retains the current behavior, which is to allow the system to guess
which character encoding is in use. However, it should be noticed that this is
almost always wrong for non-UTF8 records with non-ASCII characters. Specifying
a character set is much more reliable if you're not using UTF-8.

Rebased to use Template::Toolkit instead of HTML::Template::Pro.

Signed-off-by: Jared Camins-Esakov <jcamins@bywatersolutions.com>
Signed-off-by: Nicole C. Engard <nengard@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>