feature #36621 Log deprecations on a dedicated Monolog channel (l-vo)

This PR was squashed before being merged into the 5.1-dev branch.

Discussion
----------

Log deprecations on a dedicated Monolog channel

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Tickets       | https://github.com/orgs/symfony/projects/1#card-35233930
| License       | MIT
| Doc PR        |

This PR allows to activate a specific channel for deprecations.

## Base configuration

```yaml
monolog:
    handlers:
        #...
        deprecation:
            type: stream
            path: "%kernel.logs_dir%/%kernel.environment%.deprecations.log"
        deprecation_filter:
            type: filter
            handler: deprecation
            max_level: info
            channels: ["php"]
```

## Deprecation specific channel enabled:

```yaml
monolog:
    channels: ['deprecation']
    handlers:
        #...
        deprecation:
            type: stream
            channels: ["deprecation"]
            path: "%kernel.logs_dir%/%kernel.environment%.deprecations.log"
```

Commits
-------

3d415cb70d Log deprecations on a dedicated Monolog channel

Author: fabpot

Resources/config/debug_prod.xml

@@ -15,12 +15,13 @@
             <tag name="kernel.event_subscriber" />
             <tag name="monolog.logger" channel="php" />
             <argument>null</argument><!-- Exception handler -->
-            <argument type="service" id="logger" on-invalid="null" />
+            <argument type="service" id="monolog.logger.php" on-invalid="null" />
             <argument>null</argument><!-- Log levels map for enabled error levels -->
             <argument>%debug.error_handler.throw_at%</argument>
             <argument>%kernel.debug%</argument>
             <argument type="service" id="debug.file_link_formatter" />
             <argument>%kernel.debug%</argument>
+            <argument type="service" id="monolog.logger.deprecation" on-invalid="null" />
         </service>
 
         <service id="debug.file_link_formatter" class="Symfony\Component\HttpKernel\Debug\FileLinkFormatter">

Tests/DependencyInjection/FrameworkExtensionTest.php

@@ -425,7 +425,7 @@ public function testEnabledPhpErrorsConfig()
         $container = $this->createContainerFromFile('php_errors_enabled');
 
         $definition = $container->getDefinition('debug.debug_handlers_listener');
-        $this->assertEquals(new Reference('logger', ContainerInterface::NULL_ON_INVALID_REFERENCE), $definition->getArgument(1));
+        $this->assertEquals(new Reference('monolog.logger.php', ContainerInterface::NULL_ON_INVALID_REFERENCE), $definition->getArgument(1));
         $this->assertNull($definition->getArgument(2));
         $this->assertSame(-1, $container->getParameter('debug.error_handler.throw_at'));
     }
@@ -445,7 +445,7 @@ public function testPhpErrorsWithLogLevel()
         $container = $this->createContainerFromFile('php_errors_log_level');
 
         $definition = $container->getDefinition('debug.debug_handlers_listener');
-        $this->assertEquals(new Reference('logger', ContainerInterface::NULL_ON_INVALID_REFERENCE), $definition->getArgument(1));
+        $this->assertEquals(new Reference('monolog.logger.php', ContainerInterface::NULL_ON_INVALID_REFERENCE), $definition->getArgument(1));
         $this->assertSame(8, $definition->getArgument(2));
     }