[12.x] Make PendingBatch Macroable

[Luke-Shepp]

Adds Macroable to the PendingBatch class.

This allows chaining custom methods on Bus::batch, one example (and our use case) being to add better ide visibility into the available queues;

Bus::batch($jobs)->onHighQueue()->dispatch();

// instead of
Bus::batch($jobs)->onQueue('high')->dispatch();

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See previous accepted PR's of adding Macroable to other places;

• [11.x] Add Macroable and fill() to Support\Fluent #54404
• Make Illuminate\Support\Uri Macroable #55260
• [11.x] Allow TestComponent to be macroable #54359
• use Macroable trait on TokenGuard #51922
• [11.x] Add Macroable to PendingCommand #51572

[taylorotwell]

Can you use enums for your queues?

[Luke-Shepp]

@taylorotwell

Can you use enums for your queues?

Sure, you can use plain strings too. The point is to have a method there instead.

It can be used for more than picking a queue too though, as is the nature with custom macros. On other example;

Bus::batch($jobs)->thenNotify($user)->dispatch() 

Not sure why it's been closed when it's a useful feature, is in place elsewhere, and adds no additional maintenance burden to the project going forward.

Take a look at the URI Macroable PR, the same example can be achieved without a macro - and was accepted