* REFACTOR: Rename SiteSetting.disable_edit_notifications to disable_system_edit_notifications
- The older name could cause some confusion because the setting does not disable all edit notifications, only system ones.
* FIX: Add frozen_string_literal: true in the migration
* DEV: Deprecate 'disable_edit_notifications'
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
This change-set allows setting different defaults for different locales.
It also:
- Adds extensive testing around site setting validation
- raises deprecation error if site setting has the default property based on env
- relocated site settings for dev and tests in the initializer
- deprecated client_setting in the site setting's loading process
- ensure it raises when a enum site setting being set
- default_locale is promoted to `required` category.
- fixes incorrect default setting and validation
- fixes ensure type check for site settings
- creates a benchmark for site setting
- sets reasonable defaults for Chinese
