Use `cozy-client-js` instead of `cozydb`

[misstick]

Environment

• [x] delete server/,
• [x] move from client/app to /app,
• [x] merge both package.json (package.json and client/package.json),
• [x] update path everywhere from client/app to app/,
• [ ] make unit tests client side works,

Features

• [x] display all contacts into a list,
• [x] add a contact,
• [ ] update a contact,
• [ ] delete a contact,
• [ ] import from VCF,
• [x] create a tag,
• [ ] update a tag,
• [ ] delete a tag,
• ...

Waits for fixed Issues

• [ ] https://github.com/cozy/cozy-contacts/issues/310 cant't get cozy instance to define module imports,
• [ ] https://github.com/cozy/cozy-contacts/issues/311 contactsCollection.fetch(): server errorApplication is not authenticated,
• [ ] https://github.com/cozy/cozy-contacts/issues/311 contactModel.save(): realtime adapter doesnt work without local server

Data Migration

• Collections :

  • [ ] /contacts,
  • [ ] /tags,
  • [ ] duplicate,
  • [ ] filtered.

• Models :

  • [ ] /config,
  • [ ] /contact,
  • [ ] /tag.

(...)