[feature] Added hook to track task output size

[KCarretto]

What type of PR is this?

/kind feature

What this PR does / why we need it:

Adds a new field to Task, "output_size", which stores the size of the task's output. It adds a new schema hook to maintain this value any time tasks are updated with new output. This will effectively serve as a "has_output" check as well by filtering for tasks with size > 0. Ideally this implementation would also allow API callers to filter out large task outputs etc. if desired.

Which issue(s) this PR fixes:

Fixes #427

[codecov]

Codecov Report

Attention: 11 lines in your changes are missing coverage. Please review.

Comparison is base (6c77394) 71.46% compared to head (63d805b) 71.43%.

Files	Patch %	Lines
tavern/internal/ent/schema/task.go	63.33%	10 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #442      +/-   ##
==========================================
- Coverage   71.46%   71.43%   -0.03%     
==========================================
  Files         115      115              
  Lines        8835     8865      +30     
==========================================
+ Hits         6314     6333      +19     
- Misses       2412     2422      +10     
- Partials      109      110       +1     

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[cmp5987]

Sorry for the delay, happy to have this feature :)

side note: it would be a nice addition to have this mocked in test data

[KCarretto]

side note: it would be a nice addition to have this mocked in test data

It will be available on all tasks (automatically derived) 😄