fix(export PreferenceSections): integrate PreferenceSections

Description

We need to integrate PreferencesV4 into our app, but we have defined several sections for all the preferences, and want to show the section separately. For example, we define two sections: Organizations and Projects, and want to show Organizations preferences in one page, and Projects preferences in another page. Now I can use

const preferences = usePreferences();
preferences.fetchPreferencePage(tenantId, false);

to retrieve all sections, then filter out required section. Now I want to use <PreferenceSections section={section} /> to integrate it into my app, so need to export PreferenceSections.

Type of change

[ ] Bug fix (non-breaking change that fixes an issue)
[x] New feature (non-breaking change that adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Related issues

Fix [#1]()

trycourier / courier-react