Queue job profiling

[brandonkelly]

Adds basic profiling for queue jobs using the built-in queue.

Job durations are tracked based on their class, and possibly some common attributes.

Jobs can now implement ProfilableJobInterface + getProfileAttributes() to provide its common attributes that other jobs should be compared against. BaseBatchedJob does this, returning its properties for attributes, sans any properties that definitely won’t impact job duration (batchIndex, itemOffset, priority, and ttr).

craft\queue\Queue also now has a getAverageDuration() method, which takes a job ID, and returns the average of the last (up to) 5 runs of similar jobs.

[linear]

DEV-1196 Queue job profiling

Craft’s queue should start tracking job run durations in a DB table.

Jobs with common classes/attributes could then be averaged out to give the Cloud extension a sense of how long a new job might take.