Improve i18n of info window

[erral]

Info window is not properly i18nized.

See the template: https://github.com/plone/plone.app.linkintegrity/blob/master/plone/app/linkintegrity/browser/delete_confirmation_info.pt#L67

See the view:
https://github.com/plone/plone.app.linkintegrity/blob/master/plone/app/linkintegrity/browser/info.py#L94 and https://github.com/plone/plone.app.linkintegrity/blob/master/plone/app/linkintegrity/browser/info.py#L195

Template message is built in 2 steps where the number always goes first. In some languages this is not OK and the number should go afterwards.

The msgids should contain a variable and the template should use i18n:name style attribute to fill them.