Standardize message buses naming

[pamil]

References to #12546 (comment).

[lchrusciel]

We have 7 busses defined across 4 products. Each of them with a different name. We should unify this configuration.

At Sylius (https://github.com/Sylius/Sylius/blob/master/src/Sylius/Bundle/ApiBundle/Resources/config/app/config.yaml#L33-L43 ) we should change:

• sylius_default.bus to sylius.command_bus
• sylius_event.bus to sylius.event_bus
• make an alias sylius_default.bus that will point out to sylius.command_bus
• make an alias sylius_event.bus that will point out to sylius.event_bus
• Remove from event config all middleware and add allow_no_handlers

at Invoicing Plugin:

• Remove command bus and reuse sylius_default.bus. In the next version we can migrate these busses again (https://github.com/Sylius/InvoicingPlugin/blob/master/src/Resources/config/config.yml#L14-L19 )
• Explicitly declare busses on each handler (E.g. https://github.com/Sylius/InvoicingPlugin/blob/master/src/Resources/config/services/events.xml#L15 - we should look for all <tag name="messenger.message_handler" />

at Refund Plugin:

• Remove custom handlers and reuse sylius_default.bus. In the next version we can migrate these busses again (https://github.com/Sylius/RefundPlugin/blob/master/src/Resources/config/app/config.yml#L9-L34)
• Explicitly declare busses on each handler (E.g. https://github.com/Sylius/RefundPlugin/blob/master/src/Resources/config/services/command_bus.xml#L13 - we should look for all <tag name="messenger.message_handler" />

[pamil]

To add up on top of @lchrusciel's comment, these sylius_default.bus and sylius_event.bus should be marked as deprecated - https://symfony.com/blog/new-in-symfony-4-3-deprecating-service-aliases.

[GSadee]

I assume, this issue has been resolved by #12602