Issue #3272447 by alexpott, Spokje, catch, xjm: Update to PSR/log v3

composer.lock

composer/Metapackage/CoreRecommended/composer.json

core/composer.json

core/lib/Drupal/Core/Logger/LoggerChannel.php

core/lib/Drupal/Core/Logger/RfcLoggerTrait.php

core/modules/dblog/src/Logger/DbLog.php

core/modules/syslog/src/Logger/SysLog.php

...m/tests/modules/error_service_test/src/Logger/TestLog.php

core/modules/update/tests/src/Unit/UpdateFetcherTest.php

core/tests/Drupal/Tests/Core/Logger/LoggerChannelTest.php