Bug 26338: Show tool plugins run in tools home

Bug 26338: Show tool plugins run in tools home

In tools home there is a link to the table showing tool plugins.
Would be great to be able to run a tool plugin directly from tools home.

Also adds the behavior than if there is no tool plugin, "Tool plugins"
section is not displayed in tools home.
No need of a link that goes to an empty table ;)

Test plan :
1) Enable plugins, dont install any
2) Go to "Tools" module : /cgi-bin/koha/tools/tools-home.pl
3) Check you dont see "Tool plugins"
4) Install a tool plugin like Carrousel https://inlibro.com/instructions-carrousel/
5) Refresh /cgi-bin/koha/tools/tools-home.pl
6) Check you see "Tool plugins" and a link to Carrousel
7) Click on link to Carrousel => You see plugin run
8) Disable Carrousel plugin
9) Refresh /cgi-bin/koha/tools/tools-home.pl
10) Check you dont see "Tool plugins"

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>