Why this change?
This is a follow-up to 86b2e3aa3e.
Basically, we want to allow people to select more than 1 category as well.
What does this change do?
1. Change `type: category` to `type: categories` and support `min` and `max`
validations for `type: categories`.
2. Fix the `<SchemaThemeSetting::Types::Categories>` component to support the
`min` and `max` validations and switch it to use the `<CategorySelector>` component
instead of the `<CategoryChooser>` component which only supports selecting one category.
Why this change?
On the `/admin/customize/themes/<:id>` route, we allow admins to edit
all settings via a settings editor. Prior to this change, trying to edit
and save a typed objects theme settings will result in an error on the
server.
Why this change?
When creating a new theme setting that does not have a corresponding row
in the `theme_settings` table, we end up writing to the database twice
because `ActiveRecord::Base#save!` is called once before the `value`
or `json_value` column is updated again with another database query with
another call to `ActiveRecord::Base#save!`.
What does this change do?
Adds the column to be updated to argument for the `ActiveRecord::Base#create!`
method call so that we only have one write query to the database.
Why this change?
The `/admin/customize/themes/:id/schema/name` route is a work in
progress but we want to be able to start navigating to it from the
`/admin/customize/themes/:id` route.
What does this change do?
1. Move `adminCustomizeThemes.schema` to a child route of
`adminCustomizeThemes.show`. This is because we need the model
from the parent route and if it isn't a child route we end up
having to load the theme model again from the server.
1. Add the `objects_schema` attribute to `ThemeSettingsSerializer`
1. Refactor `SiteSettingComponent` to be able to render a button
so that we don't have to hardcode the button rendering into the
`SiteSettings::String` component
Why this change?
The logic for validating a theme setting's value and default value was
not consistent as each part of the code would implement its own logic.
This is not ideal as the default value may be validated differently than
when we are setting a new value. Therefore, this commit seeks to
refactor all the validation logic for a theme setting's value into a
single service class.
What does this change do?
Introduce the `ThemeSettingsValidator` service class which holds all the
necessary helper methods required to validate a theme setting's value
