Add support for setting client properties

[jeromegamez]

As a follow-up to #132 , this PR adds support for setting client properties and capabilities, as described in

• https://www.rabbitmq.com/connections.html#capabilities
• https://www.rabbitmq.com/connections.html#client-provided-names

$connection = [
    'host'              => 'HOSTNAME',
    'vhost'             => 'VHOST',    // The default vhost is /
    'user'              => 'USERNAME', // The default user is guest
    'password'          => 'PASSWORD', // The default password is guest
    'client_properties' => [
        'connection_name' => 'It works!',
    ],
];

Without connection name	With connection name

:octocat:

[jeromegamez]

@WyriHaximus I was thinking about using

$options['client_properties'] ??= [];

instead of

if (!isset($options['client_properties'])) {
    $options['client_properties'] = [];
}

That would be inconsistent with the other checks, though. Is this something I could/should propose in a separate PR?

[WyriHaximus]

@WyriHaximus I was thinking about using

$options['client_properties'] ??= [];

instead of

if (!isset($options['client_properties'])) {
    $options['client_properties'] = [];
}

That would be inconsistent with the other checks, though. Is this something I could/should propose in a separate PR?

Yes please, I want to make it pass PHPStan at max level before release 0.6 so all these small improvements would greatly help cleaning up the code :+1: