This feature can be enabled by choosing a destination for the
`shared drafts category` site setting.
* Staff members can create shared drafts, choosing a destination
category for the topic when it is published.
* Shared Drafts can be viewed in their category, or above the
topic list for the destination category where it will end up.
* When the shared draft is ready, it can be published to the
appropriate category by clicking a button on the topic view.
* When published, Drafts change their timestamps to the current
time, and any edits to the original post are removed.
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
