Move expires from session to session.cookies

[rclmenezes]

Moving the expires property out of session and into cookie for compatibility with express-session.

See discussion here:
#101 (comment)

Only look at most recent commit. This PR is dependent on test cleanup being merged first:
#117

No noticeable benchmark differences

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[Uzlopak]

Well. It seems odd to remove this. In the typings we describe touch to be refreshing expires value on the session. Why does it "hurt" to have the expires on the session?

[Uzlopak]

@rclmenezes
Are you aware of my question?

[rclmenezes]

To be clear, this PR is moving expires from session to session.cookies.

I'm trying to replicate what express-session does. As mentioned here, express-session stores it in the cookie:
#101 (comment)

This is an important step in making @fastify/session compatible with sessions created by express-session

[Uzlopak]

Suggested change

	cookie: { secure: true, httpOnly: true, path: '/', expires: Date.now() + 1000 }
	cookie: { secure: true, httpOnly: true, path: '/', expires: new Date(Date.now() + 1000) }

[Uzlopak]

Suggested change

	cb(null, { cookie: { expires: Date.now() - 1000 } })
	cb(null, { cookie: { new Date(expires: Date.now() - 1000) } })