FEATURE: Add WebHookEventsDailyAggregate (#27542)

* FEATURE: Add WebHookEventsDailyAggregate

Add WebHookEventsDailyAggregate model to store daily aggregates of web hook events.
Add AggregateWebHooksEvents job to aggregate web hook events daily.
Add spec for WebHookEventsDailyAggregate model.

* DEV: Update annotations for web_hook_events_daily_aggregate.rb

* DEV: Update app/jobs/scheduled/aggregate_web_hooks_events.rb

Co-authored-by: Martin Brennan <martin@discourse.org>

* DEV: Address review feedback

Solves:
- https://github.com/discourse/discourse/pull/27542#discussion_r1646961101
- https://github.com/discourse/discourse/pull/27542#discussion_r1646958890
- https://github.com/discourse/discourse/pull/27542#discussion_r1646976808
- https://github.com/discourse/discourse/pull/27542#discussion_r1646979846
- https://github.com/discourse/discourse/pull/27542#discussion_r1646981036

* A11Y: Add translation to retain_web_hook_events_aggregate_days key

* FEATURE: Purge old web hook events daily aggregate

Solves: https://github.com/discourse/discourse/pull/27542#discussion_r1646961101

* DEV:  Update tests for web_hook_events_daily_aggregate

Update WebHookEventsDailyAggregate to not use save! at the end
Solves: https://github.com/discourse/discourse/pull/27542#discussion_r1646984601

* PERF: Change job query to use WebHook table instead of WebHookEvent table

* DEV: Update tests to use `fab!`

* DEV: Address code review feedback.

Add idempotency to job
Add has_many to WebHook

* DEV: add test case for job and change job query

* DEV: Change AggregateWebHooksEvents job test name

---------

Co-authored-by: Martin Brennan <martin@discourse.org>

app/models/web_hook.rb

@@ -7,6 +7,7 @@ class WebHook < ActiveRecord::Base
   has_and_belongs_to_many :tags
 
   has_many :web_hook_events, dependent: :destroy
+  has_many :web_hook_events_daily_aggregates, dependent: :destroy
 
   default_scope { order("id ASC") }