[5.5] Feature: configurable logger channel name

[ralphschindler]

Monolog (unfortunately) does not allow post-instantiation of the base logger to change the Monolog::$name. This makes it impossible to change the name away from the environment specified one inside configureMonologUsing without a significant amount of code using reflection.

This patch is non-intrusive, and only introduces the ability to use app.log_channel if it is set by the user (this is a similar workflow to app.log_maxfiles.

References on others having the same problem:

• https://stackoverflow.com/questions/39611693/change-monolog-channel-in-laravel
• https://laracasts.com/discuss/channels/laravel/you-cant-change-monolog-channel-name

Sample code required to change the name after instantiation:

       $this->app->configureMonologUsing(function (Logger $logger) {
            $r = new \ReflectionObject($logger);
            $name = $r->getProperty('name');
            $name->setAccessible(true);
            $name->setValue($logger, env('APP_NAME'));
            ...

(If you should require a test, I would be more than happy to create one, but I noticed ServiceProviders don't normally have tests in the test suite.)

[lucasmichot]

, null is useless here

[ralphschindler]

True, I can remove it if y'all would like.