Bug 8753 - Various little things - removing new dependency, changes to errors, textua...

Bug 8753 - Various little things - removing new dependency, changes to errors, textual updates

Koha already has a sub that creates salts, so lets use that instead of math::Random::secure, so as not to add a new dependency.

Made the references to "Forgotten password" consistent, including adding it to the title of the page.

Also removed the individual error for "this email doesn't belong to this account" as that could expose the existence of a login, which I think we'd rather not do.

Made some of the text more grammatically correct, and more library specific.

To test:

Apply on top of all of the other patches.

All the usual checks, plus make sure there are no typos in any text references.

Signed-off-by: Marc Veron <veron@veron.ch>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>