When setting an old TL based site setting in the console e.g.:
SiteSetting.min_trust_level_to_allow_ignore = TrustLevel[3]
We will silently convert this to the corresponding Group::AUTO_GROUP. And vice-versa, when we read the value on the old setting, we will automatically get the lowest trust level corresponding to the lowest auto group for the new setting in the database.
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
