[9.x] Improve testability of batched jobs

[jasonmccreary]

This implements a number of empty interface methods relating to batched jobs making it easier to test batched jobs were dispatched, cancelled, or deleted.

Before this PR, it was not possible to test that a batched job was cancelled. For example:

Bus::fake();

$batch = Bus::batch([])->dispatch();
Cache::put('batched-automation', $batch->id);

Shift::runAutomation('v9.29.0'); // cancels previous batched job

Bus::assertDispatched(UpdateRepositories::class);
$this->assertTrue($batch->cancelled());

After this PR, the test above would pass.

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Submitted from 37,000ft over the Gulf of Mexico.

[jasonmccreary]

Glad to remove the fakeBatch() if you feel it's not helpful. Furthermore, is this something I should put directly on the Bus facade?