…e session handler with a DSN (nicolas-grekas)

This PR was merged into the 4.4 branch.

Discussion
----------

[HttpFoundation][FrameworkBundle] allow configuring the session handler with a DSN

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Tickets       | -
| License       | MIT
| Doc PR        | -

```yaml
framework:
    session:
        handler_id: 'redis://localhost'
        handler_id: '%env(REDIS_URL)%'
        handler_id: '%env(DATABASE_URL)%'
        handler_id: 'file://%kernel.project_dir%/var/sessions'
```

etc.

the database connection is not shared with the ORM (don't mess with transactions.)
redis/memcached connections are shared between cache and session.
(as a reminder, cache and ORM share the db connection: we're ok with trashing the cache on a rollback)

Lock-related changes are a follow up of #34043.
(fabbot failure is false positive)

Commits
-------

de9c61f [HttpFoundation][FrameworkBundle] allow configuring the session handler with a DSN

…Jan Christoph Beyer)

This PR was merged into the 4.4 branch.

Discussion
----------

[HttpFoundation] fix redis multi host dsn not recognized

| Q             | A
| ------------- | ---
| Branch?       |  4.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | Fix #34477
| License       | MIT

#34177 added support configurating session handlers with DSNs. It was no possible to pass a redis-DSN like
`redis:?host[localhost]&host[localhost:6379]&host[/var/run/redis.sock:]&auth=my-password&redis_cluster=1'`

since the check was
`case 0 === strpos($connection, 'redis://'):`

Commits
-------

81ba07a fix redis multi host dsn not recognized