Bug 10480: Remove useless routines and irrelevant pod lines

Bug 10480: Remove useless routines and irrelevant pod lines

This patch makes the following cleanup actions for all plugins:

1- Remove sub plugin_parameters. This function is not used.
2- Remove empty plugin or empty plugin_javascript subs.
3- Remove empty Blur, Clic or Focus routines from javascript.
4- Remove pod lines (copy-pasta) only referring to the 3 plugin subs.
5- Remove the last 1; line. It is no longer needed.

Test plan:
Run the unit test t/db_dependent/FrameworkPlugins.t
Test some cataloguing plugins in addbiblio.
Test some item plugins in additem and neworderempty.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
I also checked the syntax of all plugins with perl -c.
And checked the pod (if any) with podchecker: Two files still produce a
warning; the follow-up deals with them: unimarc_field_686a/_700-4.pl.

Signed-off-by: Brendan Gallagher <brendan@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>