The customize routes add CSS classes that make these admin
config pages look different from the ones under /admin/config.
We want all config routes to be under /admin/config as well.
This commit moves the emoji, user fields, and permalinks pages
out of customize and into config, updating all references and
adding more rails routes as needed.
Also renames admin emojis route to emoji, emoji is singular and plural.
Setting tab should be added to permalinks so admins do not need to have left `/permalinks`.
A new component called `AreaSetting` was added to avoid duplications and
simplify adding settings to other sections.
Redesign the permalinks page to follow the UX guide. In addition, the ability to edit permalinks was added.
This change includes:
- move to RestModel
- added Validations
- update endpoint and clear old values after the update
- system specs and improvements for unit tests
1. Use `this.` instead of `{{action}}` where applicable
2. Use `{{fn}}` instead of `@actionParam` where applicable
3. Use non-`@` versions of class/type/tabindex/aria-controls/aria-expanded
4. Remove `btn` class (it's added automatically to all DButtons)
5. Remove `type="button"` (it's the default)
6. Use `concat-class` helper
