[V2][Sessions] Make it super easy/fast to use CSRF tokens with sessions (SPA & regular apps)

[LoicPoullain]

Issue

Adding a CSRF protection is quite daunting in Foal. This should be made easier. Laravel gives a good example of an easy solution: https://laravel.com/docs/7.x/csrf

Solution

Always generate a session token when creating a session (even if the CSRF protection is disabled, otherwise it could lead to issues if enabling the protection later).

Maybe integrate the protection in @TokenRequired directly with the possibility of disabling the protection @TokenRequired({ cookie: true, csrf: false }). It would also integrate the setCsrfToken function.

[LoicPoullain]

Resolved in v2.