Hooks: `language.*`#67

Language is a feature of the whole site and it would be nice to manage the operations as add/update/delete. Language hooks are needed if:

• Language based fields/selections
• To allow certain numbers or languages
• To prevent updates and deletions in the languages required for stable and healthy operation of the application (to prevent corruption by the end user)
• …

Hooks can be:

• language.create:before
• language.create:after
• language.update:before
• language.update:after
• language.delete:before
• language.delete:after