[ResetPassword & VerifyEmail] fix templated email "lifetime" being mutated by timezones

[jrushlow]

Currently in the twig email templates, the This link will expire in 1 hour(s). is malformed if a timezone is set either in twig or in PHP.

In the controllers of both ResetPassword & VerifyEmail(RegistrationController) the token lifetime is expressed as int X. The lifetime is then passed to the twig templated email where it is ultimately passed to the date filter. This PR enforces that the lifetime value should always be formatted in the UTC timezone.

This is only a temporary solution. Ideally, either the ResetPasswordBundle & VerifyEmailBundle or MakerBundle should use a math based method to transform the lifetime value to a human readable format. e.g

$lifetime = 3600;   // seconds

public function convertToHours(int $lifetime): string

$result = ::convertToHours($lifetime);
// 1 hour

Refs SymfonyCasts/reset-password-bundle#119

[javiereguiluz]

I'm probably missing something, but the g format outputs "12-hour format of an hour without leading zeros". So, if it's 8:35 AM it outputs 8 and if it's 17:21 PM it outputs 5.

that's why I think the text requires some rewording like this:

will expire in ... hour(s) --> will expire at ...

[jrushlow]

Closing this PR in favor of a better solution. Both ResetPassword and VerifyEmail will soon have built in translation support for the token / signature expiration time. Once this is available, we'll update the templates in a new PR here in maker.. This should also facilitate an easier path forward to adding those bundles to the demo app..

See:
SymfonyCasts/reset-password-bundle#135
SymfonyCasts/verify-email-bundle#43